NASA/TM–2010-215853

The Astrophysics Science Division Annual Report 2009

William Oegerle and Francis Reddy, Editors

Pat Tyler, Graphical Editor

March 2010
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NASA/TM-2010-215853

The Astrophysics Science Division Annual Report 2009

William Oegerle

NASA Goddard Space Flight Center, Greenbelt, Maryland

Francis Reddy

SP Systems, Inc., Greenbelt, Maryland

Pat Tyler, Graphical Editor

SP Systems, Inc., Greenbelt, Maryland

March 2010

National Aeronautics and 

Space Administration

Goddard Space Flight Center

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Available from:

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7115 Standard Drive 5285 Port Royal Road

Hanover, MD 21076-1320 Springfield, VA 22161
iii

Astrophysics Science Division: Research and Missions

Contents

Introduction....................................................................................................................................1

I. 2009: Year in Review...............................................................................................................3

II. Research .................................................................................................................................5

The Persistent Gamma-ray Sky.........................................................................................5

The Transient Gamma-ray Sky..........................................................................................6

Pulsar Discoveries with Fermi ...........................................................................................7

Observable Signatures of Merging Black Holes ................................................................8

NGC 5408 and the Case for Middleweight Black Holes ....................................................9

Solar Wind Charge Exchange X-ray Emission ................................................................11

Number Counts of Far-Ultraviolet Galaxies.....................................................................13

MCW 419 and the Keck Interferometer ...........................................................................14

Eta Carinae: A Rosetta Stone or an Exception?..............................................................15

Earth as an Extrasolar Planet..........................................................................................17

III. Awards...................................................................................................................................19

IV. Research and Development ..................................................................................................21

Suborbital Projects ................................................................................................................21

Balloon-borne Experiment with a Superconducting Spectrometer (BESS).....................21

Super Trans-Iron Galactic Element Recorder (Super-TIGER).........................................22

Cosmic Ray Energetics and Mass (CREAM) ..................................................................22

X-ray Quantum Calorimeter (XQC) and Micro-X .............................................................23

Proto-EXIST.....................................................................................................................25

Gamma-Ray Burst Polarimeter........................................................................................25

X-ray Advanced Concepts Testbed (XACT).....................................................................27

Primordial Inflation Polarization Explorer ........................................................................28

Technology Development ......................................................................................................29

High-energy Laboratory Astrophysics Using an X-Ray Microcalorimeter with an Electron 

Beam Ion Trap .................................................................................................................29

X-ray Calorimeter Development ......................................................................................31

X-ray Mirror Development: IXO and NuSTAR .................................................................32

Coded-Mask and CdZnTe Detector Development ..........................................................33

Phase Fresnel Lens Development for X-ray & Gamma-ray Astronomy ..........................33

Far-Infrared Detectors .....................................................................................................34

Variable-delay Polarization Modulators for Exploring Inflation.........................................35

MKID Detectors for Submillimeter Astronomy .................................................................36

Technology Development for Space-Based Imaging Interferometers .............................37

Wide-field Imaging Interferometry Testbed......................................................................39

Technology Development for LISA...................................................................................40

Three-Dimensional Track Imager Detector for Gamma-ray and Neutron Imaging..........42

Photon Counter Detector Development...........................................................................43

V. Projects..................................................................................................................................45

Projects in Operation .............................................................................................................45

The Fermi Gamma-ray Space Telescope........................................................................45

The Rossi X-ray Timing Explorer.....................................................................................46

XMM-Newton Guest Observer Facility ............................................................................47

Swift.................................................................................................................................48

Suzaku (Astro-E2) ..........................................................................................................49

INTEGRAL.......................................................................................................................50
Astrophysics Science Division: Research and Missions

iv

Hubble Space Telescope: SM4 and Wide Field Camera 3..............................................51

The Galaxy Evolution Explorer (GALEX).........................................................................55

High Energy Astrophysics Science Archival Research Center (HEASARC) ...................57

Wilkinson Microwave Anisotropy Probe (WMAP) ............................................................60

Projects in Development .......................................................................................................60

James Webb Space Telescope .......................................................................................60

Astro-H.............................................................................................................................61

Gravity and Extreme Magnetism SMEX (GEMS) ...........................................................62

Mission Concepts ..................................................................................................................64

Absolute Spectrum Polarimeter (ASP) ............................................................................64

International X-ray Observatory (IXO) .............................................................................64

Joint Dark Energy Mission (JDEM)..................................................................................65

The Fourier-Kelvin Stellar Interferometer (FKSI) ............................................................67

Stellar Imager (SI)............................................................................................................68

Extrasolar Planetary Imaging Coronagraph (EPIC).........................................................69

Laser Interferometer Space Antenna (LISA)....................................................................71

Advanced Technology Large Aperture Space Telescope (ATLAST)................................72

VI. Education and Public Outreach in NASA’s Astrophysics Science Division............................75

E/PO within the Astrophysics Science Division ...............................................................75

HEASARC E/PO..............................................................................................................76
1

Astrophysics Science Division: Research and Missions

Introduction

The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and 

most diverse astrophysical organizations in the world, with activities spanning a broad range of topics in theory, 

observation, and mission and technology development. Scientific research is carried out over the entire electromagnetic spectrum—from gamma rays to radio wavelengths—as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three orbiting astrophysics missions—WMAP, 

RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space Telescope. A number 

of key technologies for future missions are also under development in the Division, including X-ray mirrors, 

space-based interferometry, high-contrast imaging techniques to search for exoplanets, and new detectors operating at gamma-ray, X-ray, ultraviolet, infrared, and radio wavelengths.

ASD has a strong suborbital research program, with four balloon programs and three sounding rocket programs 

at present. The Division also supports research in the astronomical community through the High Energy 

Astrophysics Science Archive Research Center (HEASARC), which now also contains Cosmic Microwave 

Background data, as well as support services for observers using the Fermi, Suzaku, Integral, XMM-Newton, 

GALEX, RXTE, WMAP, and Swift missions. Finally, ASD has a strong Education and Public Outreach 

program, to convey the exciting discoveries from NASA missions to school teachers, students, and the public.

ASD staff includes 365 people, most of whom are scientists and engineers, along with a support staff of software 

programmers, resource analysts, and administrative personnel. There are about 80 civil servant scientists, and a 

much larger number of contractor and university-based scientists. Several dozen postdoctoral fellows and graduate students are also in residence. 

Organizationally, there are five laboratories within ASD: the Astroparticle Physics Lab (code 661; Neil Gehrels, 

chief); the X-ray Astrophysics Lab (662; Rob Petre, chief); the Gravitational Astrophysics Lab (663; Joan 

Centrella, chief); the Observational Cosmology Lab (665; Jonathan Gardner, chief); and the Exoplanets and 

Stellar Astrophysics Lab (667; Jennifer Wiseman, chief). Alan Smale heads the High Energy Astrophysics Science 

Archive & Research Center (HEASARC) Office, Phil Newman heads the Office of Scientific Computing, and 

Felicia Jones-Selden leads the Instrument Development Group. Division management includes William Oegerle 

(Director), Felicia Jones-Selden (Deputy), Curtis Odell (Assistant), Kim Weaver (Associate for Science), and 

Harley Thronson (Associate for Advanced Concepts). 

The overriding goals of ASD are to carry out cutting-edge scientific research, provide Project Scientist support 

for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and support the astronomical 

community, and enable future missions by conceiving new concepts and inventing new technologies.

William Oegerle

Director, Astrophysics Science Division

NASA Goddard Space Flight Center
Astrophysics Science Division: Research and Missions

2
3

Astrophysics Science Division: Research and Missions

I. 2009: Year in Review

The year 2009 was an amazing year in ASD, one that 

saw the culmination of decades of work in the smashing successes of the first year of operation of the Fermi 

Gamma-ray Space Telescope and the rebirth of the 

Hubble Space Telescope with Servicing Mission 4. It 

was also a year of new beginnings with the selection of 

Gravity and Extreme Magnetism (GEMS) as NASA’s 

next astrophysics Small Explorer. In a look to the future, we expended significant effort to support many 

teams in the preparation of their mission concept 

studies to the National Academy’s Astro2010 Decadal 

Survey of Astronomy. 

Fermi was launched in mid-2008, and initial science 

results were already coming out by the end of 2008, 

but the tidal wave of results did not begin until 2009. 

Twelve NASA Press releases containing Fermi results 

were issued in 2009, on a wide-variety of topics: discovery of the most extreme gamma-ray burst ever, release of an all-sky map of gamma-ray sources, observations of flaring active galactic nuclei and blazars, and 

setting limits on the constancy of the speed of light 

at different frequencies. A symposium dedicated to 

the new results from Fermi was held in Washington, 

D.C. in November 2009, with many scientists from 

ASD involved in the organization. The event was celebrated by an original music composition (“Cosmic 

Reflection”) and performed at the Kennedy Center for 

the Performing Arts (see www.classicalarchives.com/

CR for more).

After many years of preparation and waiting, HST 

Servicing Mission 4 finally took place in October 

2009. Unless you have been at the far reaches of the 

Earth, you probably know that this was a phenomenal success—with the installation of WFC3, COS, 

and the repair of ACS and STIS. The Hubble Project 

Scientists in ASD (Leckrone, Niedner, Kimble, Carpenter, and Rinehart) were involved for many years 

in preparation for SM4 and deserve our thanks and 

recognition for their efforts. A much longer description of the new upgraded Hubble appears later in this 

document in the “Operating Missions” section.

GEMS (Jean Swank, PI) was selected as a SMEX in 

June 2009. GEMS will open up a new frontier in astrophysics through its high sensitivity in measuring 

the polarization of X-rays. GEMS observations will 

reveal how spinning black holes affect space-time as 

matter is drawn in and compressed by strong gravitational fields, what happens in the super-strong magnetic fields near pulsars and magnetars, and how 

cosmic rays are accelerated by shocks in supernova 

remnants. The GEMS instrument in being built at 

GSFC, and there are many ASD scientists involved in 

the mission and its science (Jahoda, Deputy PI; Kallman, Deines-Jones, Angelini, Hill, Petre, Strohmayer, 

Serlemitsos, Morris, Soong, and Black). GEMS will 

launch in 2014.

Significant progress was made during the year on our 

Soft X-ray Spectrometer (SXS) instrument for the 

Astro-H mission. Rich Kelley is the SXS PI. SXS combines a lightweight Soft X-ray Telescope (SXT) paired 

with an X-ray Calorimeter Spectrometer (XCS), providing non-dispersive 7 eV resolution in the 0.3–10 

keV bandpass. SXS passed its Key Decision Point-B 

review in June 2009, allowing the project to enter 

Phase B. In addition, NASA has accepted a proposal 

from the team for a “Science Enhancement Option” 

that will set up a General Observer program to support U.S. scientists. A Guest Observer Facility will be 

created at GSFC to develop data analysis software, observing support tools and provide GO funding to the 

community. Astro-H will launch in ~ 2014.

Significant progress is being made in the area of X-ray 

optics. We are producing the mirror substrates for 

the NuSTAR SMEX (Harrison, PI), and this is going extremely well—the mirror shapes are better than 

required. Will Zhang also continues to make excellent 

progress on glass mirrors for IXO, and so far the limit 

has been set only by the quality of the mandrels. So, 

we have optimism that the IXO requirement of ~3 

arcsec (half-power diameter) mirrors is attainable.

Significant effort was expended during the year to 

support requests for information from the Astro2010 

Decadal Survey, largely for the strategic missions 

LISA, IXO, JDEM, EXIST, and ATLAST (a concept 

for the next-generation large-aperture UVOIR telescope to succeed HST and JWST). Most of the work 

was completed by August 2009, and then we settled 

in for the long wait for the final report of the Decadal 

Survey, to be released in September 2010. 
Astrophysics Science Division: Research and Missions

4

The LISA group (Centrella, Baker, Stebbins, Camp, 

Livas, Merkowitz, and Thorpe) continues to develop 

technologies for that mission. Thorpe is involved in 

the ESA LISA Pathfinder mission data analysis. This 

mission will launch in ~2012 to retire some LISA 

technology risks. Centrella and Baker have begun a 

new initiative to compute the electromagnetic signatures from merging black holes. Steve Merkowitz began a detail to OSTP in Fall 2009.

During the year, we did receive one piece of disappointing news—cancellation of our SAFIRE instrument (Moseley, PI) being built to fly on SOFIA. 

There were no technical reasons for the cancellation; it 

was solely due to tight budgets in the SOFIA project. 

The team continues to develop state-of-the-art far-IR 

instrumentation and looks forward to future opportunities on SOFIA or other missions.

ASD scientists continue to support the development 

of the James Webb Space Telescope (Mather, Gardner, 

Clampin, Greenhouse, Rauscher, Bowers, Kimble, 

and Sonneborn). The first pieces of hardware for the 

Instrument module began arriving at Goddard in Fall 

2009. We are delivering the NIRSpec detectors and 

the NIRSpec microshutter assembly to ESA in 2010. 

Please see the full description of JWST activities in the 

“Missions Under Development” section later in this 

document.

In 2009, several ASD scientists were selected to serve 

on important NASA advisory committees or working groups. Aki Roberge has been appointed to the 

Exoplanetary Program Analysis Group (ExoPAG). 

This group reports to the NASA Advisory Committee 

(NAC) astrophysics subcommittee (APS). Sally Heap 

serves on the APS. Dominic Benford has recently been 

selected to serve on the JDEM Interim Science Working Group (ISWG). This working group will advise 

the JDEM Project on mission concept design and science requirements. 
5

Astrophysics Science Division: Research and Missions

II. Research

A few representative research programs in ASD are 

described below.

The Persistent Gamma-ray Sky

Astronomical catalogs are resources that enable scientific discovery, and the first catalog from the Large Area 

Telescope on the Fermi Gamma-ray Space Telescope is 

no exception. Based on the first eleven months of data, 

the 1FGL (Fermi Gamma-ray LAT) catalog contains 

1,451 sources, more than five times the number in 

the third EGRET catalog. The catalog emphasizes the 

growing diversity of gamma-ray source classes. Some 

features:

• Although blazars are the largest source class, there 

are non-blazar Active Galactic Nuclei seen, including radio galaxies and radio-loud narrow-line 

Seyfert 1 galaxies.

• Pulsars now encompass not only energetic young 

pulsars, but also millisecond pulsars and pulsars 

discovered in blind searches of the LAT gammaray data. 

• New source classes include high-mass X-ray binaries, supernova remnants, globular clusters, and 

starburst galaxies. 

Gamma rays from pulsar wind nebulae (PWNe) and 

supernova remnants (SNR) are particularly important 

in revealing sites of particle acceleration to high energies in our Galaxy. The Crab PWN spectrum from the 

LAT now extends to high enough energies to overlap 

with ground-based TeV observations, confirming that 

this inverse Compton emission arises from energetic 

electrons and is ultimately powered by the spin-down 

energy loss of the Crab pulsar. The Vela PWN, by 

contrast, shows that the electrons producing the GeV 

LAT emission must be a different population from the 

ones producing the TeV emission, with the LAT emission linked to the radio synchrotron radiation and the 

TeV-producing electrons related to those that produce 

the X-rays. 

At least three SNR are now seen as spatially resolved 

sources by the LAT, with morphology and energy spectra indicating that these SNR are, as long expected, 

sites of proton cosmic-ray particle acceleration. The 

gamma rays come from the energetic protons interacting with gas clouds near the SNR. 

On a much larger scale, detailed observations of the 

Large Magellanic Cloud and of two starburst galaxies 

illustrate the importance of gamma-ray observations 

for studies of star-forming regions. The emission from 

the LMC is concentrated near the 30 Doradus region, 

known as a site of intense star-forming activity. Starburst galaxies M82 and NGC253 would not be visible 

to LAT unless their production of cosmic rays is much 

stronger than seen in our own galaxy. This cosmic-ray 

excess is directly connected to the high rate of star formation that gives starburst galaxies their name. 

Equally interesting are some of the mysteries that 

emerge from the 1FGL work:

• Why are clusters of galaxies not seen, when several models predicted gamma radiation from such 

sources?

• Why do many of the unidentified EGRET sources not appear in the LAT analysis?

• What is the nature of the more than 600 1FGL 

sources with no clear associations with objects 

seen at other wavelengths?

Multiwavelength studies of many of these gamma-ray 

sources should help extend results on known source 

classes and answer the questions raised by the catalog.

NASA/DOE/Fermi LAT Collaboration
Astrophysics Science Division: Research and Missions

6

models, as it would require a huge bulk Lorentz factor, 

high upstream magnetic fields, and extremely efficient 

particle acceleration. These observations may require 

us to change our thinking of emission mechanisms 

during GRB afterglow. Simultaneous multiwavelength observations, which so far we have had only 

with GRB090510, will be needed to understand the 

physical conditions and emission mechanisms in this 

phase of the GRB.

Of course, the most unique feature of the LAT observations is the detection of high-energy photons 

(typically up to around 30 GeV). The dominant absorption process for high-energy gamma-rays is pair 

production with lower-energy photons. The degree of 

attenuation depends on the density of lower-energy 

photons, which appears enormous in GRB. If we can 

detect these high-energy photons, then the physical 

conditions in the emission region must be such that 

the photons can escape. This implies a constraint on 

the density of lower-energy photons, which in turn 

implies a lower limit on the bulk relativistic motion 

(so that the photon flux in the rest frame of the source 

is lower than that inferred from the observer frame observations). The lower limits on the bulk Lorentz factor for LAT-detected bursts are very high (~>1000) for 

both long- and short-duration GRB, suggesting that 

the short bursts are just as highly relativistic as long 

ones—an open question prior to Fermi’s launch. 

The very high photon energies, large distances, and 

short durations of gamma-ray bursts makes them 

unique probes of some properties of intergalactic 

space. By looking for differences in the arrival times 

of high- and low-energy gamma-rays, we can set constraints on the constancy of the speed of light. The 

The Transient Gamma-ray Sky

The study of gamma-ray bursts (GRB) and other shortduration transients combines the power of both instruments on Fermi. Observations with the Large Area 

Telescope (LAT) have more than tripled the number 

of bursts detected above 100 MeV. The Gamma-ray 

Burst Monitor (GBM) ties the frontier high-energy 

LAT observations to the better-known properties at 

lower energies by providing light curves and spectra 

from 8 keV to 40 MeV. 

High-energy gamma-rays seen by LAT 

always continue for a longer time than 

the low-energy gamma-rays, in some cases 

exhibiting behavior that is reminiscent 

of the afterglows observed in the radio, 

optical, and X-ray bands.

There is a saying that “when you have seen one gamma-ray burst, you have seen one gamma-ray burst.” 

In other words, that each one exhibits quite unique 

properties. Interestingly, this has not been the case for 

the high-energy gamma-ray behavior being explored 

in detail for the first time by the Large Area Telescope 

(LAT) on Fermi. The onset of the LAT emission above 

100 MeV consistently lags that of the GBM and the 

brightest LAT-detected gamma-ray bursts all show 

evidence of a distinct additional spectral component 

(indicating a distinct emission mechanism). This may 

naturally suggest that the high-energy gamma-rays 

could be produced by a population of relativistic protons, which compared to the electrons responsible for 

producing the soft gamma-rays, have a longer acceleration time. This would explain both the time delay 

and the separate spectral component. We may be getting closer to the holy grail of identifying extragalactic 

sources of high-energy cosmic-ray acceleration.

An additional common theme is that the high-energy 

gamma-rays seen by LAT always continue for a longer 

time than the low-energy gamma-rays, in some cases 

exhibiting behavior that is reminiscent of the afterglows observed in the radio, optical, and X-ray bands. 

The presence of high-energy photons (>~30 GeV) observed by LAT during the afterglow phase is extremely 

challenging to explain with conventional synchrotron 

Map of the sky in celestial coordinates showing the 

locations of the GBM-detected gamma-ray bursts, 

as well as those detected by Swift and LAT.
7

Astrophysics Science Division: Research and Missions

Pulsar Discoveries with Fermi

Since its launch in June 2008, discoveries of new gamma-ray pulsars by the Fermi Gamma-Ray Space Telescope have increased the population by a factor of 10. 

The pulsed emission from rotation-powered pulsars, 

which are compact neutron stars spinning with periods between a few milliseconds and several seconds, is 

dominant at gamma-ray energies and such pulsars are 

the most numerous gamma-ray sources in our galaxy 

in the GeV (billion electron-volt) band. Since there 

were previously only seven rotation-powered pulsars 

known to produce pulsed gamma rays, this will produce a huge leap in our understanding of pulsar physics. Of the 62 currently detected gamma-ray pulsars, 

24 have been discovered through a blind frequency 

search using Fermi data alone; the rest were discovered 

using radio or X-ray ephemerides. Since only three of 

these have subsequently been found to also be weak 

radio pulsars, the majority are thought to be either 

radio-quiet or radio-weak. 

very large distances to GRB mean that even small 

changes in the photon propagation speed may result 

in measurable delays. The very high photon energies 

make this constraint interesting because some models 

of quantum gravity allow an energy-dependent speed 

of light of the form: vph=c-Eph/MQG, where MQG is expected to be less than or equal to the Planck mass of 

(2.43 × 1018 GeV/c2

). 

The highest-energy photon in GRB 090510 arrived 

in time with the low-energy gamma-rays, so no evidence of dispersion. This photon arrived 900 ms seconds after the onset of the GRB. The redshift (and 

thus distance) of the GRB was known from optical 

spectroscopic observations of the GRB afterglow to be 

0.9. By making an assumption that the high-energy 

photon could not have been produced before the GRB 

started, we can set a constraint on the maximum time 

delay (900 ms) and thus obtain a lower limit on MQG, 

which exceeds the Planck mass and thus rules out a 

family of quantum gravity models. Lorentz invariance 

is not violated. Einstein still rules. 

Nature
Astrophysics Science Division: Research and Missions

8

The new Fermi results will require an overhaul of our 

previous ideas of electron-positron production from 

pair cascades in these sources and may imply that the 

MSPs have an unusual magnetic field structure or evolution.

Observable Signatures of Merging Black Holes

The numerical relativistic astrophysics group and the 

LISA data analysis group of the ASD Gravitational 

Astrophysics Laboratory continue studies of merging 

binary black hole systems. These are predicted to be 

among the most energetic astronomical events, releasing energy as much as 1055 erg/s in the form of gravitational radiation. Consequently, they are among the 

key target sources for gravitational wave observation.

Mergers of stellar-scale systems occur in the sensitivity band of ground-based observatories such as the 

Laser Interferometer Gravitational Wave Observatory 

(LIGO). The Laser Interferometer Space Antenna 

(LISA) will be sensitive to mergers of massive black 

hole systems ranging from roughly 10,000 to 10 million solar masses at cosmological distances (to z ~10 

and beyond). These observations form the basis for 

many of LISA’s science goals. 

A surprisingly large number of the new gamma-ray 

pulsars (15) have millisecond rotation periods, part of 

a population of “recycled” pulsars that have been spun 

up by accretion of matter from a binary companion. 

The first nine gamma-ray millisecond pulsars (MSPs) 

were found by use of radio timing solutions. More recently, new millisecond pulsars have been discovered 

through radio searches at the locations of unidentified 

Fermi sources. To date, 18 MSPs have been discovered in this way, with the expected gamma-ray pulsations having been detected from five of them using 

the derived radio ephemerides. It is expected that all 

of these will turn out to show gamma-ray pulsations 

when their radio timing solutions are in hand. Since 

most of the new MSPs are in binary systems, the gamma-ray pulsations would be impossible to find with 

blind search alone. In fact, a sizeable number (at least 

4–5) are in “Black Widow” systems, where the MSP 

wind is ablating its companion. 

Beyond their importance for understanding pulsar 

emission, these new MSPs will aid in the direct detection of the stochastic gravitational wave background 

due to merging black holes. Those that achieve radio 

timing to less than 100 ns accuracy will become part 

of the MSP timing arrays that may make the first direct detection of gravitational waves.

Resolution of a 30-year controversy has come through 

study of the light curves, spectra, and population characteristics of Fermi gamma-ray pulsars. From them, 

we have learned that the emission is being produced 

in the outer magnetospheres of the pulsars, rather than 

near the neutron star surface at the polar caps. Most 

of the gamma-ray light curves show sharp and narrow 

double peaks, as predicted by outer magnetosphere 

models to arise from special relativistic effects as the 

pulsar rotates. Phase-resolved spectroscopy in finer 

phase bins is now possible with Fermi for a number 

of the brighter pulsars, and study of the spectral variations with pulse phase will be able to probe the structure of the magnetosphere and the geometry of the 

emission. Modeling of the light curves of the millisecond pulsars, which resemble those of young pulsars, 

suggest that the emission comes from narrow acceleration gaps in the outer magnetosphere in most cases. 

This was a surprise since MSPs, with their very low 

spin-down rates, were not expected to have such narrow radiation gaps that require robust pair cascades. 

Frame from a three-dimensional simulation of 

black hole mergers produced on the Columbia 

supercomputer at NASA’s Ames Research Center. 
9

Astrophysics Science Division: Research and Missions

Einstein’s theory of General Relativity (GR) allows 

clear predictions for the physics of these mergers, but a 

full theoretical understanding of these energetic events 

and the gravitational-wave signals they produce requires detailed supercomputer simulations integrating 

the equations of GR. Following major advances in the 

basic techniques for these simulations in 2005–2006, 

Goddard’s numerical relativistic astrophysics group 

(Baker, Centrella, Kelly, McWilliams, Van Meter, 

Boggs) continues numerical studies of a variety of configurations of comparable-mass binary systems. 

The description of the merger radiation 

provided by these numerical simulations, 

while still incomplete, provides a basis 

for drawing stronger inferences from 

gravitational wave observations.

Several of these studies have focused on providing a 

detailed characterization of the gravitational waveform 

signals generated in binary black hole mergers. These 

studies first focused on developing a thorough understanding of the gravitational-wave radiation generated by mergers of non-spinning black hole systems. 

In collaboration with researchers and the University 

of Maryland, the Goddard team developed an analytic representation of the waveforms that is consistent 

with the post-Newtonian approximation that applies 

before GR effects become too strong, but also provides a close approximation to the numerical results 

describing the strong radiation generated in the final 

moments of merger. Currently, the team is working 

toward a thorough description of a broader class of 

spinning black hole systems, as well as an extension of 

the analytic waveform model to describe this broader 

class of systems. 

The description of the merger radiation provided by 

these numerical simulations, while still incomplete, 

provides a basis for drawing stronger inferences from 

gravitational wave observations. Building on the 

source modeling work, the LISA data analysis group 

(Baker, Thorpe, Arnaud, Littenberg, Kelly, McWilliams) continues investigating how the merger signal 

predictions will enhance the precision with which astronomers will be able to estimate the parameters of 

merging systems, including sky position and distance, 

with careful analysis of LISA data. In 2009, the team 

completed an investigation of this enhancement on a 

restricted class of non-spinning mergers, finding typical improvement by a factor of three in the determination of parameters for appropriate systems. A new 

study, extending this analysis to more general spinning 

mergers is underway. 

How well and when black hole binary parameters 

can be measured by LISA will have a direct impact 

on how LISA may operate in conjunction with other 

future instruments. LISA will be able to announce, 

even forecast, the time and location of merger event, 

which can then be followed up with electromagnetic 

observations.

It is not yet clear what potentially observable effects 

the strong dynamical gravity of these merging systems 

could have on any surrounding gas or other matter. 

Another Goddard team has completed an exploratory 

investigation, tracing the trajectories of particles in the 

vicinity of the merging black holes. The team (Centrella, Giacomazzo, Van Meter), in collaboration with 

additional researchers at the University of Maryland, 

is extending these studies to more realistic models of 

possible surrounding gas, as warranted by the preliminary investigations. 

The large amount of gravitational energy produced in 

these mergers can lead to a significant back-reaction 

force on the remnant black hole when the radiation is 

emitted asymmetrically. Numerical relativity simulations indicated that this “kick” imparted to the merged 

black hole can be larger than 2,000 km/s in particular 

cases. Such large kicks would have a dramatic impact 

on the relation between a merged massive black hole 

and its host galaxy or proto-galaxy, impacting astronomical expectation beyond gravitational waves. The 

Goddard team continues to study these kicks with attention to the dependence of the kick on the binary 

parameters, particularly the ratio of the two black 

holes’ masses. These results will impact the likelihood 

of large kicks in generic merging systems. 

NGC 5408 and the Case for Middleweight 

Black Holes

Astronomers have uncovered compelling evidence for 

the existence of at least two classes of black holes. The 
Astrophysics Science Division: Research and Missions

10

nosities. These objects have also shown short-timescale variability of the kind that can only be produced 

by a physically compact source, like a black hole. Indeed, many astronomers believe they are black holes, 

but the question is: How massive are they? Because in 

some cases they can be up to 100 times brighter than 

the stellar black holes we observe in the Milky Way, 

one suspicion is that some of them could be the missing middleweight black holes theory predicts. 

Weighing black holes is no simple proposition. For 

black holes in the Galaxy, the most reliable method 

is to observe the motion of its binary companion star. 

By observing its orbital motion, astronomers can use 

Kepler’s laws to deduce the mass of the black hole. 

For the ULXs in nearby galaxies, this proposition is 

extremely daunting because the companion stars are 

so very faint, so other means must be devised. 

Tod Strohmayer and Richard Mushotzky (now at University of Maryland, College Park) have been exploring new ways to estimate the masses of ULXs by measuring their X-ray timing properties and comparing 

supermassive variety that lurk at the centers of most 

galaxies—including the four-million-solar-mass behemoth at the heart of the Milky Way—and the solarmass variety that are the products of the evolution of 

massive stars. This latter group have weighed-in in the 

range from about 4–25 solar masses. But what about 

the middle ground? Where are the black holes with 

masses of about a thousand solar masses and more? 

Do they even exist? 

Theory suggests that the first generation of star formation in the early universe could produce black holes of 

several hundred solar masses, and that, due to mergers of these “primordial” holes, a whole spectrum of 

masses should have been produced that would populate the present black hole “desert” in the range from 

100–10,000 solar masses. Still other thinking suggests 

that such black holes could form in the present-day 

universe in very dense star clusters. If either of these 

ideas is valid, then where are these black holes hiding, 

and if they do exist, how can we find and weigh them?

Weighing black holes is no simple 

proposition. For the ULXs in nearby 

galaxies this proposition is extremely 

daunting. 

The answer to this puzzle may tie in with a current conundrum in observational high-energy astrophysics. 

The question concerns the nature of a population of 

extremely bright X-ray sources found in nearby galaxies. These objects have been dubbed Ultra-luminous 

X-ray sources (ULXs) because of their extreme lumiPower spectra from XMM-Newton data of NGC 

5408 X-1 showing QPO peaks at 0.01 and 0.02 Hz. 

The change in frequency accompanied by changes 

in the X-ray spectrum are also seen in Galactic black 

holes, but the QPO frequency is about 100 times 

smaller in NGC 5408 X-1, while the luminosity is 

100 times larger, suggesting that NGC 5408 X-1 

harbors a middleweight black hole.

Artist’s concept of NGC 5408 X-1.
11

Astrophysics Science Division: Research and Missions

them with the population of Galactic black holes of 

known mass. 

Many black holes in the Galaxy, whose masses we 

know, show periodic variations in their X-ray fluxes. 

The periods of these oscillations—technically called 

quasiperiodic oscillations, or QPO—appear to correlate with the mass of the black hole. This is perhaps 

not surprising, as the time it takes for an oscillatory 

wave to propagate in a cavity depends on the size of 

the cavity; bigger, more massive black holes basically 

have bigger resonance cavities. Strohmayer and Mushotzky have been using the XMM/Newton observatory 

to search for similar QPOs in ULXs and have found 

them in two objects so far: M82 X-1 and NGC 5408 

X-1. In each case, the periods of the QPOs are longer than seen in Galactic black holes, suggesting more 

massive black holes in the ULXs. 

The most intriguing case is that of NGC 5408 X-1. 

Recent observations spaced two years apart found that 

the QPO period in NGC 5408 X-1 had increased. 

The period increase was accompanied by a drop in the 

X-ray flux from the accretion disk, the same behavior that has been observed in the Galactic black holes, 

suggesting that the same physical processes are being 

observed. Whereas the typical oscillation period in 

the Galactic black holes is one second, in NGC 5408 

X-1 it is 100 seconds. Moreover, the X-ray luminosity 

is also about a 100 times greater in NGC 5408 X-1 

than comparable Galactic black holes. These relatively 

simple arguments suggest that NGC 5408 X-1 is at 

least 100 times more massive than stellar-mass Galactic black holes, and would make it one of the best 

candidates for a middleweight black hole of more than 

1,000 solar masses. 

The only way NGC 5408 X-1 can be so bright is that 

it must be devouring lots of matter. This amount of 

matter could only come from a binary companion 

star, and likely a rather massive one. Strohmayer has 

been using the Swift observatory to monitor the X-ray 

flux from NGC 5408 X-1 about twice per week for almost two years now. Swift is the only current observatory with both the imaging sensitivity (provided by its 

X-ray Telescope) and the observing flexibility to carry 

out such a monitoring campaign. 

Enough data has now been collected to show that the 

flux from NGC 5408 X-1 varies with a 115-day period. This is very likely the orbital period of the blackhole binary. The relatively long orbital period indicates 

that the companion star must be a “bloated” giant or 

supergiant. Only such a star would be big enough to 

be able to lose the requisite amount of matter to the 

black hole. More XMM-Newton observations are in 

the works to further pin down the mass of NGC 5408 

X-1, but so far it represents one of the best cases for 

the elusive middleweight black holes.

Solar Wind Charge Exchange X-ray Emission

In the last few years, solar wind charge exchange 

(SWCX) emission from the heliosphere and Earth’s 

magnetosheath has been identified as a significant 

contributor to the diffuse X-ray background at energies less than 1 keV. This signal can be of interest in 

studies of the solar system—or serve as an unfortunate 

contamination component in studies of the hot, diffuse plasmas in the Milky Way and beyond. To understand this emission, Dimitra Koutroumpa, Steven 

Snowden, and collaborators are pursuing both modeling and observational approaches, the most recent being a study of SWCX emission from the interplanetary 

helium-focusing cone.

Variations in the X-ray flux as a function of orbital 

phase in NGC 5408 X-1, from Swift X-Ray 

Telescope monitoring observations. Four different 

energy bands are shown. The variations with energy 

are further evidence of orbital modulation. The 

inferred orbital period is 115 days. 
Astrophysics Science Division: Research and Missions

12

SWCX X-ray emission in the heliosphere originates 

when a high-charge-state ion of the solar wind (SW) 

interacts with a neutral atom and gains an electron in 

a highly excited state, which then decays by emission 

of an X-ray with a characteristic energy of the ion. 

Within the heliosphere, the target atoms are primarily 

from the flow of interstellar (IS) neutrals through the 

solar system due to the motion of the sun through the 

local IS cloud. This material, a gas of mostly hydrogen 

(H) atoms with about 15 percent helium (He), flows 

from the direction l, b ~ 253°, 5°. This places Earth 

upstream of the sun in the IS neutral flow in early June 

and downstream in early December every year. Although both radiation pressure and gravity affect the 

H trajectories, only gravity significantly affects the He 

trajectories, which execute Keplerian orbits and form 

a “focusing cone” downstream of the Sun, resulting in 

a localized downstream enhancement of He observed 

annually by Earth-orbiting and L1 spacecraft. Heliospheric SWCX models predict an enhancement of 

SWCX X-ray emission due to the He cone structure.

Koutroumpa and Snowden used multiple XMMNewton observations of the south ecliptic pole (SEP) 

as Earth passes over the ISM helium-focusing cone to 

search for a correlation with the expected variation 

from models (Koutroumpa et al. 2009). Three observations of the SEP, coupled with three monitoring 

observations of the Hubble Deep Field-North (HDFN), were performed with XMM-Newton between late 

November and mid December 2003. In the soft X-ray 

energy range of XMM-Newton, SWCX emission 

mainly contributes to the two oxygen lines at 0.57 

keV (O VII) and 0.65 keV (O VIII). The HDF-N observations were used to normalize the SEP data (the 

scaled SEP data are shown in the figure) to eliminate 

short-term variation effects of the SW. The SW input 

to the study is based on in-situ measurements in the 

ecliptic plane (usually at L1) with the assumption that, 

on average, the SW conditions are the same for both 

the northern and southern solar hemispheres, and all 

along the LOS.

The heliospheric SWCX model was used to calculate 

the SWCX line emission for the lines-of-sight through 

the heliosphere, which are dependent on the satellite 

location and solar activity. The figure shows the viewing geometries of the XMM-Newton SEP (b = –90°) 

and HDF-N (l, b = 148°, 57°) observations associated 

with the He cone structure, as well as the resulting 

data and model O VII line intensities for each observation. The axis of the He cone angles downward from 

the ecliptic plane at ~5°, thus the northern directions 

view less of the cone—and therefore less SWCX emission—while the southern viewing direction should 

show enhanced SWCX emission from the cone. (Note 

that the model only accounts for roughly half of the 

observed fluxes but since the fields are not shadowed 10

8

6

4

2

0

Flux (photons cm-2 s-1 sr-1

)

80 70 60

Ecliptic Longitude

O VII

SEP

HDFN

SEP

HDFN

XMM Data

SWCX Model

0 1

1

HDFN

SEP

1 2 3

3 2 1

AU

AU

Top: XMM-Newton south ecliptic pole (SEP) 

and Hubble Deep Field (HDF-N) look directions 

overlaid on isodensity contours of the He cone as 

seen perpendicular to the Sun-Earth direction, in a 

cut through the He cone central longitude (~74°). 

Bottom: Data and model line intensities for the 

three coupled SEP-HDF-N observations. The SEP 

data are scaled for the observed variation of the 

HDF-N flux and then again by the model variation 

of the HDF-N SWCX flux.
13

Astrophysics Science Division: Research and Missions

from distant emission, e.g., the galactic halo, additional emission is expected.) The total SWCX enhancement in the He cone is marginally detected in 

the XMM-Newton data; however, the SEP data show 

the same trend as the model predictions, with the 

maximum emission coming from near the central He 

cone direction (near obs. 2), although the measured 

variations are much stronger than the predicted ones. 

This may be due to some residual variations of SWCX 

emission from the near-Earth environment. However, 

all three XMM-Newton observations were scheduled 

very near to the maximum density region (~10°) of the 

He cone (see lower panel in the figure), thus limiting 

the expectations of a large variation between the onand off-cone positions.

At present (Nov. 2009 to Jan. 2010), Snowden is PI 

on a new campaign of four coupled observations toward the SEP and NEP with Suzaku. The new, longer 

observations cover a larger area of the He cone (±25° 

around the central He cone longitude) that will allow 

a clearer detection of the soft X-ray enhancement in 

the center of the cone. The observations took place 

during a different period of the solar cycle with respect 

to the XMM-Newton observations and will provide 

new constraints for the SWCX model assumptions on 

the SW parameter (proton flux, ion abundances, and 

anisotropy) evolution during the solar cycle.

Number Counts of Far-Ultraviolet Galaxies

The number counts of far-ultraviolet (FUV) galaxies 

as a function of magnitude provide a direct statistical 

measure of the density and evolution of star-forming 

galaxies. A team of scientists, based in ASD, is carrying 

out a study of FUV number counts with the Hubble 

Space Telescope (HST). The team members are Elysse 

N. Voyer (NASA GSFC Graduate Student Research 

Program Fellow, Catholic University of America), Jon 

Gardner (GSFC), Duilia F. de Mello (GSFC/Catholic 

University of America), Harry Teplitz (NASA/IPAC), 

and Brian D. Siana (Caltech). 

The team has used measurements of the rest-frame 

FUV (1500Å) number counts computed from data 

in the GOODS-North and GOODS-South fields. 

These data were obtained from the Advanced Camera for Surveys (ACS) Solar Blind Channel Camera 

(SBC). The SBC survey of these regions covers a total 

of ~15.94 arcmin2

. Specifically, the UDF area of the 

GOODS-S field was observed by SBC in 28 two-orbit pointings covering 3.7 arcmin2

, and smaller areas 

of the GOODS-N and -S fields were observed in 15 

five-orbit pointings covering less than 1 arcmin2 each. 

Data from the HDF area of the GOODS-N field 

from Teplitz et al. (2006) that was observed by SBC 

in 14 two-orbit pointings covering 3.77 arcmin2 were 

also included. Included in the counts were 113 FUV 

sources in the UDF area of GOODS-S, 118 FUV 

sources in the smaller GOODS-N and -S images, and 

100 FUV sources from the HDF area of GOODSN. The number counts cover an AB magnitude range 

from 20th to 29th magnitude. 

After initially measuring the raw FUV counts, an incompleteness correction was applied. This was done 

statistically, through simulations using the GOODS 

V-band galaxy catalog. After applying these completeness correction factors to the measured FUV counts, 

the results were compared to previous deep FUV 

number counts (Teplitz et al. 2006, Gardner et al. 

2000) and bright FUV number counts (Hammer et 

al. 2010, Xu et al. 2005). The counts were also compared to the most recent semi-analytical models based 

on dark matter “merger trees” that trace the growth of 

supermassive black holes and their host galaxies in the 

ΛCDM cosmology (Gilmore et al. 2009, Somerville 

et al. 2008). The FUV number counts and comparisons are plotted in the included figure. 

This plot compares FUV number counts for 

galaxies in the Ultra Deep Field, Hubble Deep 

Field-North, and GOODS-North and -South (red 

dots) with other studies (other colored symbols) and 

expectations from various models (lines).
Astrophysics Science Division: Research and Missions

14

These number counts are, on average, somewhat lower 

than those from previous studies that used observations from HST’s STIS instrument in the HDF-N 

and HDF-S (Gardner et al. 2000) and the SBC in the 

HDF-N (Teplitz et al. 2006). The differences in the 

counts are likely the result of cosmic variance; the new 

data cover more area and more lines of sight than the 

previous studies. At FUV magnitude 22.5, the slope 

of our counts connects better with the faint end of 

the Coma field counts than with the GALEX counts. 

This is likely a result of the detection/photometry 

technique used on the Coma field data by Hammer 

et al. (2010) that results in better detection efficiency 

compared to the GALEX pipeline reduction methods. 

The new number counts show good agreement with 

the ΛCDM semi-analytical models, perhaps with a 

slight preference for the WMAP5 model (Gilmore 

et al. 2009, Somerville et al. 2008). These models are 

characterized by both cosmological and galaxy formation parameters that include: photoionization squelching, quiescent star formation, burst star formation, 

merger remnants and morphology, supernovae feedback, chemical evolution, black hole growth, AGNdriven winds, and radio-mode feedback. The differences in the slopes of the models can be caused by the 

different primordial power spectrum parameters (σ8) 

that depend on the cosmology of the model, or the 

number of low luminosity galaxies used in the model. 

Previous FUV counts do not match as consistently 

with any of these models, likely due to the cosmic 

variance of the fields surveyed. The SB4/Lyα-flat SED 

model from Xu et al. (2005) is characterized by a UV 

luminosity evolution, L* ~ (1+ z)2.5, and has the same 

UV SED as a no-evolution model except for a flat 

spectrum between 1200 and 1000Å. The new FUV 

number counts show better agreement with this model at the faint end than at the bright end. 

The team is currently working to further improve the 

errors of the measured FUV number counts by including even more sources and detection area from several 

SBC observations in the HST COSMOS field. They 

are also working to calculate the FUV extragalactic 

background radiation from the resolved sources in the 

fields. An interesting extension of this study would be 

to determine the actual morphologies of the galaxies 

in this sample to try and pinpoint how galaxy environment evolves with star formation at redshifts z < 1. 

This has been an important topic of astrophysical research since the mid-1990s, when it was discovered 

that the star formation rate in the universe began to 

decline sharply at z ~ 1.

MCW 419 and the Keck Interferometer

Using the Keck Interferometer, a team of astronomers 

from Goddard Space Flight Center, (Dr. William 

Danchi is a leading coinvestigator), Caltech, JPL, and 

the Keck Observatory have peered far into a young 

planetary system, giving an unprecedented view of 

dust and gas that might eventually form worlds similar 

to Jupiter, Venus, or even Earth. Because the gas, dust, 

and debris that orbit young stars provide the raw materials for planets, probing the inner regions of those 

stars lets us learn about how Earth-like planets form. 

This team recently measured the properties of a young 

planetary system at distances closer to the star than 

Venus is to the sun. 

Using the Keck Interferometer, 

astronomers recently measured the 

properties of a young planetary system at 

distances closer to the star than Venus is 

to the sun.

The researchers used the Keck Interferometer, which 

combines the light-gathering power of both 10-meter 

W. M. Keck Observatory telescopes to act as a single 

85-meter telescope—much larger than any existing or 

planned facility. Nothing else in the world provides 

us with the types of measurements the Keck Interferometer does. In effect, it’s a “zoom lens” for the Keck 

telescopes.

The “zoom lens” allowed the researchers to probe 

MWC 419, a blue, B-type star that has several times 

the mass of the sun and lies about 2,100 light-years 

away in the constellation Cassiopeia. With an age less 

than 10 million years, MWC 419 ranks as a stellar 

kindergartner. 

With the interferometer and the increased ability to 

observe fine detail, the team measured temperatures 

in the planet-forming disk to within about 50 million 
15

Astrophysics Science Division: Research and Missions

miles of the star. That is about half of Earth’s distance 

from the sun and well within the orbit of Venus. 

For comparison, astronomers using a single telescope 

have directly observed HR 8799, Fomalhaut, and GJ 

758 and their orbiting planets, which are 40 to 100 

times farther away from their stars. 

These new results were taken in near-infrared light 

(3.5 to 4.1 micrometers), which is a wavelength slightly longer than red light and is invisible to the human 

eye. Our team used a newly implemented infrared 

camera, which is the only one of its kind on Earth, to 

make the first “L-band” interferometric observations 

of MWC 419. 

This unique infrared capability adds a new dimension 

to the Keck Interferometer in probing the density and 

temperature of planet-forming regions around young 

stars. This wavelength region is relatively unexplored. 

Basically, anything seen through this camera is brand 

new information. 

With the data, the team measured the temperature 

of dust at various regions throughout MWC 419’s 

inner disk. Temperature differences throughout the 

disk may indicate that the dust has different chemical 

compositions and physical properties that may affect 

how planets form. For example, in the solar system, 

conditions were just right to allow rocky worlds to 

form closer to the sun, while gas giants and icy moons 

assembled farther out in the system. The results have 

been reported in The Astrophysical Journal (Ragland et 

al. 2009). The observations are an important first step 

in a larger program to collect data on young stars that 

span the lower-mass T Tauri stars, which are the progenitors of sun-like stars, to their more massive counterparts, like MWC 419. 

Our team plans to study the range of developing stars 

because their mass, size, and luminosity might affect 

the composition and physical characteristics of the 

surrounding disk. The team is continuing to collect 

data on young stars and will combine their infrared 

observations with data from the Keck Interferometer’s 

“nulling” mode, which blocks out the light from the 

central star in a young planetary system.

Eta Carinae: A Rosetta Stone or an Exception?

Massive stars play key roles in both our Milky Way 

and in the distant reaches of our universe. The first 

ones, which formed out of pristine, unprocessed material from the big bang, were composed of hydrogen 

and helium. The first heavy elements formed in their 

cores and were soon ejected into the interstellar medium, eventually leading to chemically enriched gas 

and dust that led to generations of later star formation. 

What is the composition of this gas and dust? Some 

massive binaries are thought to lead to progenitors of 

distant gamma-ray bursts (GRBs) that satellites, such 

This artist’s concept shows the development of 

planets within a dust disk around a young star.

MWC 419, also known as V594 Cas, is a young, blue 

variable star located 2,100 light years away in the 

constellation Cassiopeia. The Keck Interferometer 

probed the temperature and density of the dust 

disk around MWC 419 to within a fraction of an 

astronomical unit from the star. DSS/STScI/AURUA
Astrophysics Science Division: Research and Missions

16

as Swift and Fermi, detect daily. What leads some massive binary members to become GRBs?

Astronomers do not have the luxury of studying the 

first stars in detail, but we can study massive stars in 

our own and nearby galaxies. Eta Carinae is a massive 

binary star system that is nearing the end of its life 

cycle. It is sufficiently close—only about 7,400 light 

years away—that with the power of the Hubble Space 

Telescope, astronomers can study this binary star as it 

undergoes changes on timescales within our historical 

records. At least one of the system’s stars has run out of 

hydrogen fuel and has attempted to consume helium. 

In the 1840s, astronomers saw Eta Carinae brighten 

to rival Sirius, the brightest star in the night sky. Today we see an expanding hourglass-shaped structure, 

known as the Homunculus, composed of material 

thrown out during this brightening. The Homunculus 

contains at least 12 solar masses of material that were 

ejected in that major event, yet Eta Carinae survived. 

How?

Ground-based studies and monitoring of the X-ray 

flux by the Rossi X-ray Telescope Explorer (RXTE) 

reveal that Eta Carinae has a 5.5-year period, likely 

caused by a massive binary companion. Detailed spectroscopic studies with the Chandra X-ray Observatory 

fitted by models by Julian Pittard (University of Leeds) 

and Michael Corcoran (USRA/GSFC) indicate that 

the X-rays originate from massive stellar winds colliding at high velocities. A cavity is carved out of the primary’s massive wind by a faster, less massive secondary 

wind. At the apex of their collisions, the gas is heated 

to X-ray-emitting temperatures.

The binary orbit of Eta Carinae is very elliptical in 

shape. For most of its 5.5-year period, the secondary 

star lies far from the primary. Then, for a few months, 

it plunges toward the larger star and passes deep into 

the primary wind. X-rays and far-ultraviolet radiation 

from the secondary star become trapped and the binary system goes through a low state as seen by astronomers.

In the 1840s, astronomers saw Eta 

Carinae brighten to rival Sirius, the 

brightest star in the night sky. At least 

12 solar masses of material were ejected 

in that major event, yet Eta Carinae 

survived. How?

These massive winds of Eta Carinae are resolved by the 

high angular resolution of Hubble Space Telescope, 

permitting spectroscopic studies of the extended wind 

structures throughout the binary orbit. Recently, Ted 

Gull and a team of scientists used the Space Telescope 

Imaging Spectrograph to study the variations of these 

winds as the massive binary went through its 5.5-year 

orbit. Tom Madura, a graduate student from University of Delaware working with Stan Owocki, led the 

development of a three-dimensional model of the interacting winds. Merging of the model with the observations now provides astronomers with information 

on the orientation of the binary orbit and allows them 

to test their knowledge about how massive winds interact. 

Direct Hubble image of the Homunculus, an 

hourglass-shaped nebula ejected by the Eta Carina 

binary during the 1840s outburst. The massive 

binary is beginning its final stages before becoming 

two supernovae. At least 12 solar masses were ejected 

in the 1840s, yet the two stars survived. Studies of 

this massive system gives astronomers insight on 

how massive stars evolve.
17

Astrophysics Science Division: Research and Missions

Eta Carinae, although it has a 5.5-year period, is 

gradually changing. Likely, the system is still settling 

down from the 1840s event (indeed, there was a lesser 

event in the 1890s that astronomers also observed), 

but it continues to evolve. Both stars are massive 

enough that each will evolve to become a supernova 

and eventually a black hole. The likelihood that either 

star will become a GRB is remote. Even in the early 

universe, few massive stars became GRBs, and as more 

and more heavy elements were produced, the stars that 

formed are thought to be less massive. Still, characterizing what the binary members of Eta Carinae are 

today will provide astronomers with a picture of potential GRB progenitors.

Earth as an Extrasolar Planet

By the close of 2009, astronomers had catalogued more 

than 400 extrasolar planets. These have been identified 

using radial velocity, gravitational microlensing, and 

transit techniques. In most cases, little is known about 

these worlds other than their orbital period and inclination and some bulk properties, such as approximate 

mass, radius, and density. Using these aforementioned 

techniques, we are also sometimes able to determine 

an average orbital radius and eccentricity. These are 

important findings and establish a strong observational record for exoplanetary science. 

The detection of such a trove of new planets within 

the past 15 years—beginning with the discovery of 

51 Pegasi in 1995—indicates that there may be many 

such bodies. It provides a strong motivation to learn 

more about their individual characteristics, together 

with that of their host stellar systems. Using advanced 

techniques such as transit spectroscopy, nulling interferometry, and stellar coronography, we are entering 

an epoch when we may progress past merely identifying and counting exoplanets and start to characterize 

their surfaces, atmospheres, and the exozodiacal dust 

disks theorized to frequently accompany planetary systems.

In our efforts to understand observations of extrasolar 

planets, and, in particular, to characterize exoplanets 

orbiting within the habitable zone of their host star—

roughly defined as the range of distances from the host 

for which liquid water may exist on the surface—we 

have but one reliable example: Earth. We are strongly 

motivated to study our home world as if it were an 

exoplanet to establish an understanding of chemical abundances in the atmosphere and, in particular, 

that of biomarkers—molecular bands associated with 

an active biosphere. We also wish to comprehend the 

phenomenological evidence for a liquid-water hydrosphere with implications to geomorphology. 

A slice of the winds of Eta Carinae. Left: A direct image of Eta Carinae, the star buried within the Homunculus. 

Middle: A portion of a long-slit spectrum centered on doubly-ionized iron ([Fe III] 4703Å) that reveals the 

boundary of the colliding winds. Right: A similar spectral portion centered on singly-ionized iron ([Fe II] 

4814 Å) that shows the extent of the massive primary wind. Buried deep within the central core are two 

massive stars that total over 100 times the mass of our sun.

PA=22°

PA=27°

PA=38°
Astrophysics Science Division: Research and Missions

18

Scientists within the ASD are vigorously active in this 

area of research. For example, we have recently obtained Earth observations from a range of about 11 

million miles using the High Resolution Instrument 

on the Deep Impact spacecraft. These observations, 

conducted under the Extrasolar Planet Observation 

and Characterization (EPOCh) mission, for which 

Dr. Drake Deming of the Planetary Systems Laboratory (GSFC) is Co-PI, have provided us with lowresolution spectra of Earth’s atmosphere, images of 

Earth in various phases, and spatially resolved images 

of Earth’s surface. From these observations, we are able 

to describe our home planet in an abstract way that 

may be useful for exoplanet researchers.

One such study, led by Dr. Richard K. Barry of the 

Laboratory for Exoplanets and Stellar Astrophysics, 

seeks to characterize bright patches or “glints” noted in 

many of the individual Earth images. Calculations and 

analysis of the data show these glints are likely specular reflection of sunlight from the surfaces of bodies 

of water (see figure). The team has analyzed the photometry of these glints to characterize the reflecting 

surface and the layers of atmosphere traversed and to 

catalog the specific bodies of water associated with the 

glints. This allows the team to see geomorphological 

trends in the strength of the reflections, which appear 

to be a weak function of the isolation of the body of 

water. Additionally, the team is working closely with 

co-investigators at several universities to simulate these 

observations using the NASA Astrobiology Institute’s 

Virtual Planetary Laboratory 3-D spectral Earth model and have matched visible, multi-wavelength 24-

hour light curves of Earth to within three percent at 

most wavelengths. 

These observations of Earth and the advanced models 

used to simulate them will be important not only in 

assisting our understanding of new exoplanet data but 

will prove crucial in feasibility studies for future space 

missions to detect and characterize earth-like planets. 

Photometry of an 8-pixel-diameter patch centered 

on the calculated sun-Earth-observer specular 

reflection point, corrected for the solar spectrum. 

The upper four traces indicate the total flux. The 

lower four traces show the total flux minus the flux 

contributed from other sources, such as clouds. 

Center wavelengths of the four 100 nm filters 

segmenting the observed spectral range are 0.35 mm 

(blue), 0.55 mm (green), 0.75 mm (yellow), 0.95 mm 

(red). This analysis will be useful in understanding 

future observations of exoplanets and confirming 

models of Earth’s atmosphere.
19

Astrophysics Science Division: Research and Missions

III. Awards

In the past year, a number of awards were received by 

individuals or teams within the Astrophysics Science 

Division (ASD) for extraordinary contributions to 

their respective fields. See the 2008 report for awards 

extending back to approximately 2006.

In January 2009, two ASD 

scientists were recognized. 

Dr. Peter Serlemitsos of 

the X-ray Astrophysics 

Laboratory was awarded 

the American Astronomical Society’s Joseph 

Weber Award for Astronomical Instrumentation. 

The award recognizes the 

design, invention or significant improvement of 

instrumentation leading 

to advances in astronomy. The contributions of Serlemitsos led to major advances in both X-ray optics 

and multiwire proportional counters. These advances 

enabled many ground-breaking missions, including 

OSO-8, HEAO-1, RXTE, BBXRT, ASCA, Suzaku, as 

well as the upcoming Astro-H mission. 

In the same month, Neil 

Gehrels, who heads the 

Astroparticle Physics 

Laboratory, was awarded 

the 2009 Henry Draper 

medal by the National 

Academy of Sciences. The 

citation reads: “For his 

pioneering contributions 

to gamma-ray astronomy. His leadership of the 

Compton Gamma Ray 

Observatory and the Swift 

Mission has led to new insights into the extreme physics of active galactic nuclei and gamma ray bursts.” 

The National Academy of Science only presents this 

award every four years. 

In February 2009, Dr. Marc Kuchner, a member of 

the Exoplanets and Stellar Astrophysics Lab, was a recipient of an SPIE Early Career Achievement Award 

“in recognition of his 

outstanding achievements 

that have greatly facilitated the detection and characterization of extra-solar 

planets. His invention and 

refinement of new telescope coronagraph masks 

provide astronomers with 

innovative tools needed 

to detect planets directly 

around bright stars.” The 

award is given annually to 

an early career professional in recognition of significant and innovative technical contributions to a field 

of science and/or engineering.

In March 2009, we learned 

that Dr. David Leckrone 

was awarded NASA’s Distinguished Service Medal. 

This award is “the highest 

honor that NASA confers. 

It may be awarded to any 

person in the Federal service who, by distinguished 

service, ability, or courage, 

has personally made a 

contribution representing 

substantial progress to the 

NASA mission. The contribution must be so extraordinary that other forms of recognition would be inadequate.” The award was bestowed for his leadership, 

through many servicing missions, of the Hubble Space 

Telescope. The medal was awarded in a ceremony at 

NASA HQ on April 16, 2009. 

Dr. Steven Ritz, previously a member of the 

Astroparticle Physics Lab 

and now at the University 

of California, Santa Cruz, 

was awarded the NASA 

Outstanding Leadership 

Medal for his leadership 

as NASA Project Scientist 

for the Fermi Gamma-ray 

Space Telescope. The fabulous success of this misDr. Peter Serlemitsos

Dr. Neil Gehrels

Dr. Mark Kuchner

Dr. David Leckrone

Dr. Steven Ritz
Astrophysics Science Division: Research and Missions

20

sion, as described elsewhere in this report, is due in no 

small part to his expert guidance and hard work. 

Two groups in ASD also brought home NASA 

Achievement Awards in 2009—the BESS Polar Team 

(a large team of scientists from universities and institutions in Japan and the U.S.), for a record-setting circumpolar flight of the BESS balloon to search for cosmic antimatter, and the “Afterschool Universe Team” 

for Public Service in Education and Outreach. The 

Afterschool Universe program is intended for middle 

school students (grades 6–8). The Team includes Anita Krishnamurthi (now at the AAS), Sarah Eyermann, 

Sara Mitchell, George Gliba, Pat Tyler, Jim Lochner, 

and Chris Reynolds (at University of Maryland). The 

Afterschool Universe website is universe.nasa.gov/au.

Dr. Kimberly Weaver, 

Associate Director for 

Science in ASD, received 

the Distinguished Alumna 

award from the University 

of Maryland Astronomy 

Department for her efforts 

in promoting science. Kim 

has an exceptional ability 

to convey the excitement 

of scientific discovery to 

the community, and we 

thank our colleagues at 

the University of Maryland for their recognition.

The Swift Mission Team received the Maria and Eric 

Muhlmann Award from the Astronomical Society of 

the Pacific. The award is given for recent significant 

observational results made possible by innovative advances in astronomical instrumentation, software, or 

observational infrastructure. 

Dr. Harvey Moseley received the Distinguished 

Presidential Rank Award 

for 2009. Quoting from 

the U.S. Office of Personnel Management web site: 

“Each year, the President 

recognizes and celebrates 

a small group of career Senior Executives and senior 

career employees with the 

Presidential Rank Award. 

Recipients of this prestigious award are strong leaders, professionals, and scientists who achieve results and consistently demonstrate 

strength, integrity, industry and a relentless commitment to excellence in public service.” The award for 

Harvey was in recognition of his decades of service 

to NASA in developing innovative new instrumentation and detectors to explore the universe (COBE, 

X-ray calorimeters, IRAC, detectors for HAWC, TES 

arrays, and microshutters). Harvey is only the third 

scientist in NASA to win this award—another was 

John Mather—so this is something special indeed. As 

is customary, Harvey will receive his award in a ceremony at the White House early in 2010.

Dr. Kimberly Weaver

Dr. Harvey Moseley
21

Astrophysics Science Division: Research and Missions

ceptances of ~ 0.3 m2 sr, BESS and BESS-Polar are the 

largest balloon-borne magnet instruments.

GSFC is responsible for the outer scintillators, the 

instrument electronics, and the Cherenkov detector 

PMTs. BESS-Polar integration and testing takes place 

at GSFC and GSFC co-leads launch and flight operations. GSFC has principal responsibility for instrument performance analysis.

No antinucleus heavier than an 

antiproton has been detected in BESS 

flights through BESS-Polar I. These data 

have provided the most stringent reported 

test of the presence of heavier antinuclei 

in the current universe.

BESS-Polar I flew for 8.5 days in 2004—at a transient period prior to solar minimum—and reported 

1,512 antiprotons. BESS-Polar II recorded data with 

the magnet energized for 24.5 days in 2007–2008, flying near solar minimum, when the sensitivity of the 

antiproton measurements to a low-energy primary 

component is greatest, and has detected 8,000–10,000 

antiprotons. Depending on the antiproton energy, this 

is 10–20 times the combined BESS 1995/97 statistics. 

The instrument performed very well, and analysis of 

13.5 terabytes of data obtained on 4.7 billion cosmicray events is nearing completion. 

No antinucleus heavier than an antiproton has been 

detected in BESS flights through BESS-Polar I. These 

data have provided the most stringent reported test of 

the presence of heavier antinuclei in the current universe, with a 95% confidence upper limit of 2.7 × 10-7

for antihelium/helium. If no antihelium is detected in 

BESS-Polar II data, this will be lowered by about a 

factor of ~ 3.

BESS has also carried out the only search to date for 

antideuterons, which may be produced in local processes—including the evaporation of PBH and supersymmetric particle annihilation—and has reported an 

upper flux limit of 3 × 10-4 (m2

 s sr GeV/nucleon)-1. 

The BESS-Polar II instrument could not be recovered 

in 2008 because its flight was terminated late in the 

IV. Research and Development

Suborbital Projects

Balloon-borne Experiment with a 

Superconducting Spectrometer (BESS)

BESS is a highly successful U.S.-Japan program that 

uses elementary particle measurements to study the 

early universe and provides fundamental data on the 

spectra of light cosmic-ray elements and isotopes. 

BESS measures the energy spectra of cosmic-ray antiprotons to investigate signatures of possible exotic 

sources, and searches for heavier antinuclei that might 

reach Earth from antimatter domains formed during 

symmetry-breaking processes in the early universe. 

BESS is led jointly by GSFC (PI, John Mitchell) and 

KEK, the Japanese High Energy Accelerator Research 

Organization (PI, Akira Yamamoto). Hams and Sasaki 

are co-investigators. Collaborating institutions in the 

U.S. are the University of Denver and the University 

of Maryland, and in Japan, the University of Tokyo, 

Kobe University, and ISAS/JAXA. 

The BESS collaboration carried out nine conventional 

northern-latitude flights between 1993 and 2002, recording 2,237 cosmic-ray antiprotons and confirming 

that the majority are secondary products of the interactions of primary cosmic-ray nuclei with interstellar 

gas. Flights near solar minimum in 1995 and 1997, 

however, observed low-energy antiproton flux slightly 

in excess of purely secondary expectations. This may 

suggest a contribution from an exotic primary source, 

such as the evaporation of small primordial black holes 

(PBH) with initial mass around 5 × 1014 g, or the annihilation of candidate dark matter particles. 

The BESS-Polar instrument was developed to greatly 

increase sensitivity using long-duration balloon flights 

over Antarctica. The BESS-Polar magnetic-rigidity 

spectrometer uses a unique superconducting magnet 

with a thin coil and cryostat and a precision trajectory-tracking system. A plastic scintillator time-of-flight 

system, with two layers at the top and bottom of the 

instrument and one layer inside the magnet bore, below the tracker, measures the charge and velocity of 

incident particles. A silica aerogel Cherenkov detector 

rejects light background particles. With geometric ac-
Astrophysics Science Division: Research and Missions

22

Super-TIGER has a total area of 5.6 m2 and is only 60 

cm thick to maximize its geometric acceptance. The 

detector layout and minimal column density give an 

effective geometry factor of 2.5 m2 sr at Z = 34—seven 

times larger than TIGER. Super-TIGER can accomplish its goals in two typical long-duration Antarctic 

flights, with the first planned for 2012. 

Super-TIGER will measure the 

individual abundances of elements 

over the range 30 ≤ Z ≤ 42 with high 

statistical accuracy to test and clarify the 

emerging model of cosmic-ray origin in 

OB associations and models for atomic 

processes by which nuclei are selected for 

acceleration.

Super-TIGER is a forerunner of the ENTICE (Energetic Trans-Iron Composition Experiment) instrument on the OASIS (Orbiting Astrophysical Spectrometer in Space) mission. OASIS has been studied 

with NASA funding as an Astrophysics Strategic Mission Concept and was presented for consideration by 

the Astro2010 Decadal Survey. In a three-year mission, ENTICE would provide the first statistically 

significant elemental-abundance measurements in the 

actinide range.

Cosmic Ray Energetics and Mass (CREAM)

The balloon-borne CREAM instrument was developed for direct measurements of cosmic-ray spectra 

1 ≤ Z ≤ 26 at total energies greater than 1011 eV to 

test models of cosmic-ray acceleration. In addition, 

CREAM measurements of the energy-dependent 

abundance ratios of secondary cosmic-ray species to 

their primary progenitors test models of cosmic-ray 

transport and storage in the Galaxy. The CREAM collaboration includes the University of Maryland (PI, 

Eun-Suk Seo), GSFC, Pennsylvania State University, 

Ohio State University, Ewha Woman’s University (Korea), Kyung Pook National University (Korea), KAIST 

(Korea), LPSC Grenoble (France), CESR Toulouse 

(France), and UNAM (Mexico). John Mitchell is the 

GSFC Institutional PI and Link is a co-investigator.

season and in a remote location. BESS-Polar II was 

successfully recovered in 2009/10, and the instrument 

is returning to GSFC for evaluation and refurbishment.

Super Trans-Iron Galactic Element Recorder 

(Super-TIGER)

Super-TIGER is a new, large-area balloon-borne instrument under development by Washington University in St. Louis (PI, W. Robert Binns), Caltech, GSFC, 

and JPL. John Mitchell leads the Super-TIGER effort 

at GSFC and co-investigators are Christian, De Nolfo, 

Hams, Link, Sasaki, and Barbier (now at NASA HQ). 

Super-TIGER will measure the individual abundances 

of elements over the range 30 ≤ Z ≤ 42 with high statistical accuracy to test and clarify the emerging model 

of cosmic-ray origin in OB associations and models 

for atomic processes by which nuclei are selected for 

acceleration. Exploratory measurements with lower 

statistics will extend to Z = 56. Super-TIGER will also 

measure, with excellent statistical precision, the energy 

spectra of the more abundant elements 14 ≤ Z ≤ 28 at 

energies 0.8 ≤ E ≤ 10 GeV/nucleon. These measurements will permit a sensitive test of the hypothesis that 

microquasars or other phenomena could superpose 

features on the otherwise smooth energy spectra. 

Super-TIGER is based on experience with the smaller 

TIGER instrument that was flown from Antarctica in 

2001 and 2003 for a total of 50 days and produced the 

first measurements of individual element abundances 

for 31Ga, 32Ge, and 34Se. Super-TIGER measures the 

charge and energy of incident nuclei using three layers of plastic scintillator, together with Cherenkov 

detectors employing both acrylic and silica aerogel 

radiators. Scintillating optical fiber hodoscopes give 

the trajectories of individual particles to enable corrections for pathlength through the detectors, detector response maps, and interactions in the atmosphere 

and in the instrument. 

GSFC is responsible for both the acrylic and aerogel 

Cherenkov detectors, the scintillators, the mechanical 

structure of the instrument and payload, and the highvoltage system. In addition, instrument and payload 

integration will be carried out at GSFC. 
23

Astrophysics Science Division: Research and Missions

days; 2005–2006, 28 days; 2007–2008, 29 days; 

2008–2009, 19.5 days; and 2009–2010, 41 days. The 

flight of CREAM-VI is planned for the 2010–2011 

austral summer. 

X-ray Quantum Calorimeter (XQC) and 

Micro-X

The X-ray Quantum Calorimeter (XQC) is a broadband, non-dispersive X-ray spectrometer built to study 

the soft X-ray background in the band from 0.05 

to 2  keV. The ASD research team members include 

Scott Porter, Richard Kelley, Caroline Kilbourne, and 

Megan Eckart. Collaborating institutions include the 

University of Wisconsin (Madison) and the University 

of Miami.

The spectrometer was built to differentiate the spectral 

components that are thought to make up the ubiquitous soft X-ray background, including emission from 

the Local Bubble, the Galactic halo, and solar-wind 

charge exchange in the exo-atmosphere and the heIn a series of long-duration balloon flights, CREAM 

will accumulate the large exposure needed to measure 

the energy spectra of the most common elements up to 

about 1015 eV. At these energies, most measurements 

have been based on the detection by ground-based 

instruments of the showers of particles produced by 

interactions of primary cosmic rays in the atmosphere. 

These indirect measurements can only infer the identity of the incident particle. Direct measurements by 

CREAM will provide invaluable information on cosmic-ray composition, as well as the calibration data 

required to interpret airshower results. 

The combined CREAM and airshower data will test 

models of Fermi shock acceleration of cosmic rays 

in supernova remnants. Standard models for this 

mechanism predict that a rigidity-dependent acceleration limit should be reached, resulting in a progressive composition change with increasing energy from 

dominance by light elements to dominance by heavier 

elements. CREAM measures the charge of incident 

nuclei using a plastic scintillator timing detector and 

a silicon pixel detector. Depending on the energy and 

species of the incident particle, its energy is measured 

by a silica-aerogel Cherenkov camera (CREAM-III, 

IV, V), a transition radiation detector (CREAM-I), 

or a tungsten-scintillating optical-fiber calorimeter 

(all versions). The geometric acceptance of the TRD 

is ~ 1.3 m2sr and the effective geometric acceptance 

(including interactions) for the calorimeter is about 

~0.3 m2sr for protons and greater for higher Z nuclei. 

A new TRD is being prepared by CERN (Switzerland) 

and JINR (Russia) to facilitate improved measurements of secondary-to-primary ratios.

GSFC responsibilities are to provide an acrylic Cherenkov detector for rapid particle identification—to 

preferentially trigger the instrument on nuclei heavier 

than He—and a scintillating optical-fiber penetration 

detector that aids triggering on high-energy events 

and gives a reference time for the timing scintillators. 

GSFC also supports integration and test of CREAM 

as well as launch and flight operations. 

Originally designed for the anticipated ultra-longduration balloon capability, CREAM has flown five 

times over Antarctica in long-duration flights, accumulating 159.5 days of exposure: 2004–2005, 42 

The XQC payload uses a 6 × 6 pixel X-ray calorimeter 

array develop and produced at GSFC. Each pixel in 

the array is 2 mm × 2 mm, and utilizes a 0.8-mmthick HgTe X-ray absorber. The detector array has 

an energy resolution better than 8 eV FWHM at 

600 eV and has a nominal operating band from 

0.05 to 2 keV. NASA/XQC
Astrophysics Science Division: Research and Missions

24

The XQC has flown four times since 1995, with the 

most recent flight in March 2008. The fourth flight 

used a detector array with four times the collecting 

area of previous flights and is based on technology 

developed for the Astro-E2 program. The data from 

the fourth flight is currently being processed, but preliminary results show significant contributions from 

C IV, O VII, OVIII, Fe XVII, and Fe XVIII. Previous 

flight have placed constraints on certain types of dark 

matter, and have detected and placed limits on Local 

Bubble emission from M-shell transitions in Fe IX, X, 

and XI. Flight 5 of the XQC is planned for late 2010 

and will use a new, refined version of the large-area 

detector design for flight 4. The XQC detectors for 

flight 5 were fabricated in late 2009, and X-ray absorber testing is currently underway.

The Micro-X payload is designed to be the first X-ray 

calorimeter payload using focusing X-ray optics. It 

uses significant design heritage from the XQC program, including a very similar adiabatic demagnetization refrigerator. However, the detector and readout 

technology are derived from the IXO program. The 

ASD research team members include Porter, Kelley, 

Kilbourne, Simon Bandler, Joseph Adams, Eckart, 

Stephen Smith, Peter Serlemitsos, and Yang Soong. 

Collaborating institutions include the University of 

Wisconsin (Madison), MIT, University of Miami, 

University of Florida, and the National Institute of 

Standards and Technology. 

The Micro-X payload will use a 121-pixel (11 × 11) 

X-ray calorimeter array with superconducting transition edge (TES) thermistors operating at 50 mK. 

It is designed to have an energy resolution of 2 eV 

(FWHM) across the energy band from 0.05 to 2 

keV. The Micro-X payload will use a focusing optic 

designed and produced at GSFC for the SXS sounding rocket that flew in 1989 and is the predecessor 

of the optics used for BBXRT, ASCA, Astro-E2, and 

Astro-H.

The Micro-X payload is scheduled to fly during 2011 

to observe the bright eastern knot of the Puppis-A supernova remnant. The detector array will be designed 

and produced by GSFC and will be read out using a 

cryogenic SQUID multiplexer and room-temperature 

electronics jointly developed by GSFC and NIST. 

liosphere. The superposition of these temporally and 

spatially variable sources can create a complicated 

spectral picture that requires high-resolution spectroscopy to unwind. Detailed spatial maps first were 

made with sounding rockets, then with ROSAT, and 

the first high-resolution spectra in the 0.25 keV band 

were made with the DXS shuttle-attached payload 

that used a scanning dispersive spectrometer. 

The XQC, however, is the first broadband non-dispersive, high-resolution spectrometer to probe the entire 

X-ray-emitting range, from M-shell Fe emission at 70 

eV up to 2 keV where the diffuse emission becomes 

dominated by unresolved extragalactic sources. In addition, the XQC payload is the first—and currently, 

the only—spaceflight implementation of an X-ray 

calorimeter array.

The XQC spectrometer is based on a 36-pixel X-ray 

calorimeter array that was designed and produced at 

GSFC. Each pixel in the calorimeter array is relatively 

large at 2mm x 2mm, and has an energy resolution 

at O VII Ka of better than 8 eV FWHM. The detector array is operated at 50 mK using a small adiabatic 

demagnetization refrigerator built at the University of 

Wisconsin. The payload does not use an X-ray optic 

since this would significantly reduce the grasp of the 

experiment, but is instead collimated to a one-steradian field of view. 

Preliminary spectrum of the soft X-ray background 

centered at galactic coordinates 30°, +60° as 

observed with the XQC during its fourth flight in 

March 2008. The spectrum shows line emission 

from several highly charged ions and is likely a 

superposition of several emission mechanisms. 

NASA/XQC
25

Astrophysics Science Division: Research and Missions

(6.5 hours at float altitude with a landing in western 

Kansas). It is lead by Josh Grindlay (CfA), with significant contributions from Goddard. 

Goddard continues the development of the Command and Data Handling (C&DH) electronics in the 

front-end detector-array electronics (i.e., everything 

after the detector ASIC). The balloon flight raised the 

TRL from 5 to 6 for the entire end-to-end detector, to 

front-end electronics (ASIC and ADC), to the datahandling electronics, and the command and control 

system. It also tested the stacked-sheet design of the 

coded-aperture tungsten mask. During the flight, 

Cygnus X-1 was successfully imaged and a spectrum 

obtained.

Proto-EXIST2 will incorporate a new ASIC that (a) 

direct bonds to the CZT detector crystals (i.e., 2D 

stud-bump bonding), and (b) has half the pitch (i.e., 

0.6mm pitch, four times as many pixels). Proto-EXIST2 will fly in the fall of 2010 from Ft. Sumner, New 

Mexico. 

Proto-EXIST3 will incorporate a slightly revised version of the direct-bond ASIC to allow four-sided closepacking (instead of the three-sided, close-packing of 

the direct-bond ASIC). It will fly in 2011.

Gamma-Ray Burst Polarimeter

The Gamma-Ray Burst Polarimeter (GRBP) is an instrument originally designed for a small U.S. Naval 

Academy (USNA) satellite called MidSTAR-2 (Joe 

Hill, PI, and K. Jahoda, co-I). USNA funding for 

MidSTAR-2 has diminished, but the design and fabrication of GRBP continued through 2009, focused 

for a mission of opportunity (MoO) on another small 

satellite or for a sounding rocket. 

The GRBP utilizes Time-Projection Chamber (TPC) 

technology in a new way to make polarization measurements of X-rays in the 2–10 keV energy band. The 

TPC polarimeter enables the design of a much higher 

sensitivity and wider field-of-view instrument. GRBP 

is designed to satisfy three requirements: 

• To demonstrate a new technology in a space environment for the first time.

GSFC will also provide the refurbished SXS X-ray optic with 200 cm2

 collecting area at 1 keV and a 2.5 

arcmin PSF. 

Micro-X will provide some of the first detailed highresolution spectra of a supernova remnant, with about 

40,000 counts expected during the flight. The payload 

will be the first opportunity to utilize high-spectralresolution, broadband, and spatial-spectral imaging, 

and will provide a glimpse of what we can expect from 

Astro-H and then IXO in the future.

Proto-EXIST

EXIST is a concept for an all-sky hard-X-ray imaging 

mission (see the mission concept section of this document for more information). ASD team members include Neil Gehrels, Scott Barthelmy, Jack Tueller, and 

Gerald Skinner. 

Proto-EXIST1 is the first of a three-phase, balloonbased instrument to develop and prove the technology 

for the EXIST mission. Proto-EXIST1 successfully 

flew in October 2009 from Ft. Sumner, New Mexico 

Proto-EXIST1 payload carried by the Columbia 

Scientific Balloon Facility launch vehicle “Big 

Bill” at Ft. Sumner, New Mexico, prior to launch 

on Oct. 9, 2009. The detector array lies within 

the pressure vessel at the bottom of the gondola. 

The coded aperture mask is on the top end of the 

pressure vessel. The long vertical tube is the star 

camera. The gondola, provided by Marshall Space 

Flight Center, is an azimuth-over-elevation design.
Astrophysics Science Division: Research and Missions

26

Left: GRBP flight design containing four 6 × 6 × 5 cm3 detector modules. Two detector units occupy a single 

gas enclosure. The frontend electronics will be mounted on the outside of the gas volume on the far side. 

Right: GRBP prototype detector module identical to the flight design. 

GRBP flight electronics boards. Top left: Engineering data system. Top right: Low-voltage power supply. Bottom left: Engineering command and data handling board. Bottom right: High-voltage power supply.
27

Astrophysics Science Division: Research and Missions

• To measure the polarization of the Crab Nebula, 

the only source for which the polarization has 

been conclusively measured in the X-ray band.

• To measure the polarization of 5 to 10 gamma-ray 

bursts (GRBs) in a two-year mission.

Polarization measurements of even a handful of GRBs 

will allow us to discriminate between different theories 

about the mechanisms behind these hugely powerful 

and enigmatic events. A demonstration of the GRBP 

instrument will increase the technology readiness level 

for future missions. 

This year, the design of the flight detectors and polarimeter enclosure have been completed. They will not 

be fabricated until a launch platform is identified and 

the interface finalized. A single detector unit and enclosure has been fabricated and is currently being tested in the lab with polarized and unpolarized X-rays. In 

April 2010, the detector will be tested at Brookhaven 

National Laboratory National Synchrotron Light 

Source. The supporting electronics, low-voltage power 

supply, high-voltage power supply, and housekeeping 

flight boards have been designed, built, and tested. 

An engineering version of the command and data handling board has been built and tested, but the flight 

design cannot be finalized until a launch platform is 

finalized. An electronics box enclosure has been designed and fabricated to accommodate these four 

boards. The front-end electronics consists of a preamp 

board and a SIDECAR ASIC board for analog to digital conversion. The preamp board has been designed, 

fabricated, and tested; slight modifications are necessary prior to flight. The software for the SIDECAR 

has been written and tested with the detector and the 

C&DH board. A few minor changes are being implemented.

The team has been investigating alternative launch 

opportunities. The most likely scenario that is compatible with the instrument delivery schedule is that 

GRBP will be tested on a sounding rocket. This will 

accomplish the first two goals and prove the design 

such that a satellite version could be built to measure 

the polarization of GRBs.

X-ray Advanced Concepts Testbed (XACT)

XACT is a new suborbital X-ray payload being developed at GSFC to test and advance Technology Readiness Levels (TRL) of several technologies that could 

enable future missions (Gendreau, PI). The scientific 

objective of XACT is to measure the X-ray polarization properties of the Crab Nebula, the Crab pulsar, 

and of the accreting binary Her X-1. Polarimetry is 

a powerful tool for astrophysical investigation that 

has yet to be exploited in the X-ray band, where it 

could provide unique insights into neutron stars, black 

holes, and other extreme-physics environments. 

With powerful new enabling 

technologies, XACT will demonstrate 

X-ray polarimetry as a practical and 

flight-ready astronomical technique.

With powerful new enabling technologies, XACT 

will demonstrate X-ray polarimetry as a practical and 

flight-ready astronomical technique. The technologies 

XACT will bring to flight readiness will also provide 

important new capabilities for NASA missions in 

space-based X-ray spectroscopy, timing, and photometry. XACT combines new ultra-lightweight optics, 

advanced photoelectric X-ray polarimeters, and novel 

calibration sources in a standard sounding-rocket payload.

The XACT optics—lightweight concentrators optimized for unresolved sources—will provide the largest focused X-ray-collecting area ever achieved on 

a sounding rocket. Currently under development at 

GSFC, they will have the largest focused collectingarea-to-mass ratio ever flown, enabling future spacebased missions that require truly enormous throughput and low background.

The XACT polarimeters are the latest innovation in 

photoelectron tracking devices that combine a large 

polarization response with high quantum efficiency 

to achieve unprecedented sensitivity. ASD scientists 

recently originated this polarimetry technique, based 
Astrophysics Science Division: Research and Missions

28

on the negative-ion Time Projection Chamber (TPC), 

and are currently developing it for astrophysical and 

heliospheric missions in the 1–100 keV band. The 

TPC polarimeter is the basis for the SMEX GEMS 

mission. XACT will leverage these efforts to deliver 

the polarimeters at a low incremental cost.

XACT will demonstrate in-flight calibration using a 

modulated electronic X-ray source that can be pulsed 

for arbitrary and commandable intervals. Such a 

source can be used to provide calibration information 

on demand. This minimizes the associated background 

and results both in higher sensitivity and observatoryscheduling freedom for future missions.

The XACT goals are accomplished with a simple flight 

plan that is well within the launch and recovery envelopes of a standard Black Brant IX at the White Sands 

Missile Range. The first launch will be in December 

2011 to observe the Crab. This will be followed by a 

second launch in June 2012 to look at Her X1.

Primordial Inflation Polarization Explorer 

The Primordial Inflation Polarization Explorer 

(PIPER) is a balloon-borne mission to measure the 

polarization of the cosmic microwave background in 

search of the signature of primordial gravity waves 

excited by an inflationary epoch in the early universe. 

Alan Kogut is the PI, and ASD team members include 

Dominic Benford, David Chuss, Dale Fixsen, James 

Hinderks, Gary Hinshaw, Harvey Moseley, Johannes 

Staguhn, and Edward Wollack. 

PIPER addresses fundamental questions at the intersection of physics and cosmology. Cosmology posits 

a period called inflation, shortly after the Big Bang, 

when the expansion of space-time accelerated dramatically to “inflate” the universe from subatomic to 

macroscopic scales. Inflation neatly explains the initial 

conditions of Big Bang cosmology (a spatially flat, homogeneous universe with scale-invariant density perturbations), but it relies on the extrapolation of physics to energies a trillion times above those accessible to 

direct experimentation in particle accelerators. PIPER 

will test inflation by measuring the polarization pattern in the cosmic microwave background caused by a 

background of gravity waves created during an inflationary epoch. Such a signal is expected too exist, with 

observable amplitude and a unique spatial signature. 

Detection of the gravity-wave signature of inflation 

would have profound consequences for both cosmology and high-energy physics. It would establish inflation as a physical reality, determine the relevant energy 

scale, and probe physics at energies near Grand Unification to provide direct observational input for a “final 

theory” of quantum mechanics and gravity.

PIPER achieves unprecedented sensitivity by combining several technologies pioneered by Goddard researchers.

1) Large-format bolometric detectors. PIPER will fly 

5,120 transition-edge superconducting bolometers 

in a Backshort-Under-Grid (BUG) architecture. By 

moving all wiring beneath the array, the BUG architecture allows efficient two-dimensional tiling of the 

focal plane without any reflective elements that would 

reduce the optical efficiency.

2) A Variable-Delay Polarization Modulator (VPM) 

injects a time-dependent phase delay between orthogonal linear polarizations to cleanly separate polarized 

Expected sky coverage and signal-to-noise ratio 

for PIPER observations of polarized Galactic 

dust emission (Mollweide projection in Galactic 

coordinates). Contours are at S/N=3, 10, 30, 100, 

and 300 per 15 arcminute beam spot at 500 mm 

wavelength. PIPER’s combination of high sensitivity 

and nearly full sky coverage are a powerful tool for 

both astrophysics and cosmology.
29

Astrophysics Science Division: Research and Missions

from unpolarized radiation. The fast (3 Hz) modulation allows full characterization of the incident radiation into Stokes I, Q, U, and V parameters on time 

scales that are fast compared to instrument drifts or 

beam motion on the sky.

3) Open-aperture cold optics. PIPER’s twin telescopes 

fit within the old ARCADE dewar and will operate 

at 1.5 K to provide background-limited sensitivity. 

Maintaining all optical elements at 1.5  K or colder 

improves sensitivity by a factor of 10 compared to 

ambient optics, allowing PIPER to use conventional 

(overnight) balloon flights instead of more challenging 

Antarctic operations,

PIPER will map the sky in both linear and circular 

polarization, at wavelengths of 1500, 1100, 850, and 

500 mm (frequencies 200, 270, 350, and 600 GHz). It 

will detect the signature of inflationary gravity waves 

to a factor of three fainter than the lowest value predicted by inflationary models. The unbiased survey of 

sub-millimeter polarization will also provide an important probe of the interstellar dust cirrus and the 

large-scale structure of the Galactic magnetic field, 

and will be the first sky survey in circular polarization 

at these wavelengths.

Technology Development

High-energy Laboratory Astrophysics Using 

an X-Ray Microcalorimeter with an Electron 

Beam Ion Trap

Our laboratory astrophysics program is designed to 

simulate astrophysical plasmas in the laboratory in order to benchmark and provide guidance to the atomic codes that form the basis of the spectral synthesis 

models used in X-ray astrophysics. These models are 

used to relate spectra observed from an astrophysical 

object to conditions in the source, including temperature, ionization-equilibrium, composition, density, 

turbulence, and bulk motion. This work is fundamentally important as X-ray astrophysics begins to use 

high-resolution spectroscopy as the dominant tool in 

exploring the physics of X-ray emitting objects. 

This has already started with the observation of bright 

point sources with the high-resolution dispersive spectrometers on Chandra and XMM-Newton. It will become critically important with the upcoming Astro-H 

and International X-ray Observatory, where every observation will produce a detailed, high-spectral-resolution image. Our program is designed to validate and 

PIPER sensitivity (red) compared to the gravitational 

wave signal predicted by WMAP (blue band). 

PIPER is an order of magnitude more sensitive than 

the European Space Agency’s Planck mission. 

Mn Ka spectrum measured with a silicon-based 

calorimeter using improved HgTe X-ray absorber 

material. More than twenty such absorber samples 

have been tested on pixels compatible with the 

design of the SXS of Astro-H, with the results 

clustered tightly around a resolution of 4 eV.
Astrophysics Science Division: Research and Missions

30

thermal distributions. Measurements are related back 

to theory, the results of atomic calculations, and to the 

standard X-ray spectral synthesis models used in X-ray 

astrophysics. 

A key instrument in these measurements is a broadband, high-resolution X-ray calorimeter instrument 

provided by GSFC beginning in 2000 and now on its 

third revision. This system has been operated almost 

continuously for the past 9.5 years. It has produced 

well over two dozen peer-reviewed articles, and it has 

made critical measurements of absolute cross sections 

in L-shell Fe and Ni, as well as charge-exchange measurements in S, C, O, and Fe. Many investigations are 

ongoing.

GSFC first installed an X-ray calorimeter instrument 

at the LLNL EBIT facility in the summer of 2000, 

based on the engineering-model detector system for 

the Astro-E observatory. The system was significantly 

upgraded using technology developed for Astro-E2 in 

2003. A dedicated facility-class instrument designed 

from the ground up for laboratory astrophysics was 

installed in 2007. The current instrument, dubbed 

the EBIT Calorimeter Spectrometer (ECS), utilizes a 

32-channel X-ray calorimeter array from the Astro-E2 

program installed in a long-lifetime, automated laboratory cryostat that enables continuous experiments 

for up to 70 hours with a two-hour recharge. The detector array is populated with 16 mid-band (0.05–12 

keV) X-ray absorbers with 4.5 eV FWHM resolution 

at 6 keV, and 16 high-band (0.1–100 keV) X-ray absorbers with 30 eV FWHM at 60 keV. 

We are currently designing and constructing the 

fourth-generation instrument that will be based on 

detector technology from the IXO development program. It will be installed in a completely automated 

cryogen-free cryostat. The fourth-generation instrument is dubbed the Transition-Edge Microcalorimeter Spectrometer (TEMS) and will be composed of 

a checkerboard hybrid of 128 low-band (0.05–1 keV) 

pixels with 0.8 eV resolution at 1 keV, and 128 midband (0.05–10 keV) pixels with 2.0 eV resolution at 

6 keV. In addition, there will be a 64-channel highband array (0.1–200 keV) with 300 eV resolution 

at 60 keV. The TEMS instrument will become the 

workhorse instrument in our laboratory astrophysics 

program to make sure that our measurements and uncorrect the accuracy of the spectral synthesis models 

in controlled ground-based experiments that will give 

us confidence that we have correctly ascribed observed 

spectral features to known conditions in the astrophysical source.

The basis of our program is a high-resolution, nondispersive, X-ray calorimeter spectrometer, a suite of 

very-high-resolution dispersive spectrometers, and 

the Electron Beam Ion Trap (EBIT) plasma generator at the Lawrence Livermore National Laboratory 

(LLNL). ASD scientists include Scott Porter, Richard 

Kelley, Caroline Kilbourne, Joseph Adams, Stephen 

Smith, Demitra Koutroumpa, and Maurice Leutenegger. Other collaborating institutions include Stanford 

University and the National Institute of Standards and 

Technology. The LLNL EBIT can produce nearly any 

plasma conditions from low charge states in light elements to bare uranium with electron beam energies of 

up to 200 keV. Nearly any charge state of any astrophysically interesting element can be produced, either 

as a pure charge state or in a Maxwellian distribution 

at known temperature. 

Non-equilibrium ionization conditions can also be 

produced with almost any astrophysically interesting 

ionization parameter. Typical measurements in our 

program include spectral-line identification, absolute 

cross sections, recombination, charge-exchange recombination, and cross sections in thermal and nonPhotograph of 32 x 32 array of TES pixels on 

0.3 mm pitch. The absorbers are composed of 

electroplated Au and Bi.
31

Astrophysics Science Division: Research and Missions

derstanding of atomic processes are ready to interpret 

the spectra we will obtain with the Astro-H and IXO 

observatories. TEMS will be installed at the EBIT facility in 2011.

X-ray Calorimeter Development

An X-ray calorimeter determines the energy of an 

incident X-ray photon by measuring a small change 

in temperature. Three types of X-ray calorimeters 

presently dominate the field, each characterized by 

the thermometer technology. The first two types use 

temperature-sensitive resistors: semiconductors in the 

metal-insulator transition and superconductors operated in the superconducting-normal transition. The 

third type uses a magnetic thermometer. These can be 

considered the three generations of X-ray calorimeters, 

although further development of each is proceeding.

The Soft X-ray Spectrometer (SXS) on Astro-H, expected to launch in 2014, will use an array of silicon 

thermistors with HgTe X-ray absorbers that will operate at 50 mK. Both the semiconductor and superconductor calorimeters have been implemented in 

small arrays. Kilopixel arrays of the superconducting 

calorimeters are just now being produced, and it is 

anticipated that much larger arrays will require the 

non-dissipative advantage of magnetic thermometers. 

Goddard Space Flight Center is the only institution 

playing a leading role in the development of each of 

the three dominant X-ray calorimeter technologies. 

The scientists of the ASD microcalorimeter team includes Joe Adams, Simon Bandler, Meng Chiao, Fred 

Finkbeiner, Richard Kelley, Caroline Kilbourne, Scott 

Porter, and Steve Smith, postdocs Catherine Bailey 

and Megan Eckart, and co-op student Jack Sadleir. 

The main development in the silicon-thermistor calorimeters since XRS/Suzaku has been in their X-ray 

absorbers. GSFC has been working closely with EPIR, 

a company that was awarded an SBIR contract to develop HgCdTe and HgTe absorbers with substantially 

lower heat capacity than the material used for XRS 

that yet thermalizes the energy of X-ray photons reproducibly and uniformly. After extended process refinement and performance evaluation, EPIR’s HgTe was 

selected for the SXS flight absorbers. Better than 4 eV 

resolution at 6 keV has been achieved using samples 

of EPIR HgTe in the size needed for SXS (0.83 mm 

wide). The SXS thermistor array itself is based heavily 

on the XRS design, but will include better heatsinking 

to reduce the impact of cosmic-ray heating. 

Over the past few years, Goddard has developed a 

microcalorimeter design that incorporates a micronsthick Au or Au/Bi absorber, designed to thermalize 

the absorbed energy quickly, with a superconducting transition-edge sensor (TES) made from a Mo/

Au proximity-effect bilayer. In this novel design, the 

absorber makes direct contact with the TES only in 

normal-metal regions that are used to reduce noise in 

these sensors, which allows the use of a high-quality 

electroplated gold layer as the foundation for the absorber. A further constraint, that the high-conductance 

absorber not electrically short out the sensor, results in 

an unusual T-shaped geometry for the contact. 

These devices consistently achieve energy resolutions 

of 2–3 eV FWHM at 6 keV. The pixels are sufficiently 

uniform that a 2 × 8 SQUID multiplexer read-out 

demonstration, done in 2008 in collaboration with 

colleagues at the National Institute of Standards and 

Technology, achieved better than 3 eV resolution in 

all 16 pixels using the common biasing inherent to 

the design of the electronics. Work towards a 3 × 32 

SQUID MUX read-out demo is in progress, in order 

to demonstrate technology needed for the InternaSchematic of the read-out circuit for meander-based 

magnetic calorimeters. As shown in the illustration 

and photograph, an X-ray absorber can be affixed 

to each meander, making possible very large, closepacked arrays. Calorimeters of this design have 

achieved 3.3 eV resolution.
Astrophysics Science Division: Research and Missions

32

tional X-ray Observatory. Arrays in a 32 × 32 format have been completed, and process refinement for 

integrating high-density microstrip wiring with such 

arrays is nearly complete. 

Goddard has also developed position-sensitive TES 

calorimeters. These devices join multiple absorbers to 

a single TES via different thermal links, and the pulse 

shape is used to determine which absorber received 

the X-ray photon. Four-absorber versions have demonstrated an energy resolution of 6 eV at 6 keV, and 

variations with larger absorbers and with more absorbers are being studied.

Goddard is part of an international collaboration 

(including Brown University, Heidelberg University, 

NIST/Boulder, and PTB/Berlin) to develop magnetic 

calorimeters. The Goddard emphasis has been on designs that can be implemented in closely packed arrays. 

Goddard has been fabricating arrays of superconducting niobium meander inductors onto which a layer of 

magnetic material (Au:Er) is deposited. When a current is passed through the meander, a magnetic field 

is produced in the magnetic material. When an X-ray 

is absorbed, the heating changes the magnetic permeability, and therefore the inductance of the meander. 

The change in inductance of the meander changes the 

current both through the meander and through the 

input coil of the SQUID. 

GSFC magnetic calorimeter arrays with absorbers 

have achieved 3.3 eV resolution at 6 keV, and there 

remains potential to substantially improve on this in 

the near future, perhaps even to under 1 eV. Positionsensitive magnetic calorimeters analogous to the TESbased version are also under development.

X-ray Mirror Development: IXO and NuSTAR

Mirror technology development for the International 

X-ray Observatory (IXO), formerly known as Constellation-X, continues at GSFC and is led by Will 

Zhang. Zhang and his team are well on their way toward meeting the IXO requirement of 5". As of this 

writing, they have been able to consistently make mirror segments that, when properly aligned and integrated, will produce 7.5" X-ray images—within a factor 

of two of meeting the IXO requirement—by using a 

glass-forming technique.

They continued a collaborative effort with Goddard’s 

Applied Engineering and Technology Directorate 

(AETD). They have completed two pairs of mandrels 

that meet IXO forming-mandrel figure requirements. 

These mandrels are being used to refine techniques 

to fabricate mirror segments and to demonstrate that 

several mandrels can be utilized simultaneously to produce mirror segments meeting both quality and schedule requirements. 

Meanwhile, they are also continuing another collaborative effort between ASD and AETD—developing 

the process of integrating these mirror segments into 

modules that, in turn, can be integrated into a flight 

mirror assembly. Using finite-element analysis tools, 

they have simulated the entire process of starting with 

individual mirror segments and finishing with them 

aligned and bonded into a module. They are engineering and implementing the process in the laboratory. 

They expect to complete a mini-module with at least 

two pairs of mirrors by 2010. They will subject the 

mini-module to both X-ray performance and environmental tests to a TRL-5 for a pre-Phase-A mission.

The Nuclear Spectroscopic Telescope Array (NuSTAR) is a Small Explorer under development (Harrison/Caltech, PI). ASD/GSFC is a member of the 

Projection of the image of a 5-mm slit formed in 

Cu Ka X-rays (8.04 keV) with a 3-mm diameter 

PFL. The focus has been trimmed with a refractive 

corrector lens. For comparison, the diffractionlimited response would correspond to 16.7 

milliarcseconds, which includes slit-magnification 

and detector-resolution effects.
33

Astrophysics Science Division: Research and Missions

team, with the responsibility of providing glass mirror 

substrates using the glass-forming technology that has 

been developed for IXO. These substrates are shipped 

to the Danish Space Research Institute to be coated 

with multi-layers to enhance their reflectivity of highenergy (10–80 keV) X-rays. They are then shipped to 

Columbia University for alignment and assembly into 

two mirror modules. 

Work began in February 2008 with facility modification and procurement of ovens and other necessary 

equipment. The work was completed on schedule and 

within budget. The entire mirror substrate production 

facility, located in Building 22 at Goddard, became 

fully operational on September 1, 2008. After a period of equipment checkout and personnel training, 

the production of flight substrates started in February 

2008. It has been on schedule and on budget. The last 

batch of flight substrates will be delivered by March 

31, 2010, helping the NuSTAR project to make its 

August 2011 launch. 

Coded-Mask and CdZnTe Detector 

Development 

It is not possible to focus gamma rays with current 

technology, so the wide-field Burst Alert Telescope 

(BAT) on Swift uses a technique called coded-aperture 

imaging to image and localize incoming gamma rays. 

Gamma rays are detected at the focal plane by 32,768 

pieces of CZT. 

ASD (Barthelmy, Tueller, Okajima) has three development efforts to improve CZT detectors for new mission applications:

• the electronics and packaging for the Proto-EXIST and EXIST missions;

• a strip detector for the InFOCuS balloon instrument;

• a pixelated detector for homeland security uses. 

The proto-EXIST and EXIST effort are described in 

the Suborbital section. 

The CZT strip detector for InFOCuS is a 20-micron 

2-D pattern of strips on 2mm CZT. ASD is working with Goddard’s Engineering Directorate on this 

effort for the actual electrode fabrication on the CZT 

material. This InFOCuS detector is 26 × 26 × 2mm 

and uses the XA1 ASIC that we have previously used 

in the pixelated InFOCuS detector and for the SwiftBAT detector array. There is also a parallel effort to 

use the newer VATAGP7 ASIC from Gamma MedicaIDEAS, Inc.

The homeland security effort involves a 20 × 20 × 5mm 

CZT crystal with an 11 × 11 pattern of pixelated electrodes. Takashi Okajima (code 662) is working with 

the Engineering Directorate on this effort.

Phase Fresnel Lens Development for X-ray & 

Gamma-ray Astronomy

Diffractive optics, specifically Phase Fresnel Lenses 

(PFLs), offer a mechanism to perform astronomical observations in the X-ray and gamma-ray energy 

regimes with diffraction-limited angular resolution. 

This translates to performing high-energy astronomy 

with milliarcsecond to microarcsecond angular resolution in the X-ray and gamma-ray bands. Furthermore, 

PFLs have high throughput at these high photonic energies and are capable of being scaled to large, metersize dimensions, which would also lead to dramatic 

improvements in source sensitivity. 

These encouraging first results are 

a major step towards demonstrating 

that the superior imaging potential of 

PFL-based optics can be performed in a 

wide X-ray/gamma-ray energy band in a 

format that is scalable for astronomical 

applications.

A group at NASA GSFC, in collaboration with the 

University of Maryland, has fabricated PFLs designed 

toward astronomical applications and characterized 

their imaging performance in an X-ray test-beam. The 

University of Maryland employed gray-scale MicroElectrical-Mechanical System (MEMS) technology 

to fabricate two different PFL designs in silicon, one 

designed to image at 8 keV and the other at 17.4 keV. 

These PFLs were characterized in the GSFC 600-meter Interferometry Testbed. They demonstrated near 

diffraction-limited performance—corresponding to 

~20 milliarcsecond angular resolution at 8 keV—with 
Astrophysics Science Division: Research and Missions

34

an efficiency 76 percent of the theoretical maximum 

(limited by an observed and understood interference 

effect induced by the specific PFL implementation). 

Initial imaging measurements on the PFLs designed 

for 17.4 keV have demonstrated imaging corresponding to ~25 milliarcsecond angular resolution; further 

development and experimentation is in progress. The 

group includes Drs. John Krizmanic, Gerald Skinner, 

Zaven Arzoumanian, Keith Gendreau, and Neil Gehrels at GSFC, and Prof. Reza Ghodsssi and his group 

at the University of Maryland. Additionally, an effort 

to fabricate binary PFLs at GSFC has been funded under a GSFC IRAD award to develop optics for solar 

imaging applications, in collaboration with Dr. Brian 

Dennis in the Heliophysics Science Division.

A key development has been overcoming one of the 

main limitations of purely diffractive optics—the narrow bandwidth in which superb angular resolution is 

obtained. The solution to this chromaticity problem 

is obtained by including a refractive component along 

with a PFL to construct an achromat. Refractive components have been fabricated at GSFC using diamond 

turning and a refractive lens was employed to “trim” 

the focal length of the 8 keV PFL, bringing the performance closer to the diffraction limit. Employing an 

inherent feature of PFLs—that the focal length is energy dependent—a proof-of-principle achromat was 

fabricated using the 17.4 keV PFL design for the diffractive component matched to an appropriate power 

refractive component. Initial test beam measurements 

determined a point-spread-function that was nearly 

flat over an energy range from 8–11.3 keV, validating 

that the chromaticity of a pure diffractive PFL can be 

overcome with a diffractive-refractive achromat. These 

encouraging first results are a major step towards 

demonstrating that the superior imaging potential of 

PFL-based optics can be performed in a wide X-ray/

gamma-ray energy band in a format that is scalable for 

astronomical applications.

Advances in formation-flying spacecraft systems make 

an eventual mission feasible, and a team of scientists 

from ASD/GSFC are collaborating with the GSFC 

Guidance, Navigation, and Control (GN&C) Systems Engineering Branch, under a GSFC IRAD award 

(Shah, PI), to further develop the formation-flying aspects. The team had developed a flight dynamics tool 

set to quantify the formation-flying requirements and 

analyze the performance of current attitude-sensor 

technologies, employing a milliarcsecond PFL-based 

X-ray imaging mission as a baseline. The team includes Krizmanic and Skinner from ASD, and Shah 

and Calhoun from GN&C.

Far-Infrared Detectors

The past decade has seen dramatic advances in many 

areas of long-wavelength astrophysics. WMAP, following the great successes of Cosmic Background Explorer (COBE), has confirmed our general understanding 

of the early universe and allowed us to quantify critical 

parameters—its age, composition, and early evolution. Spitzer has provided an extraordinary imaging 

and mid-infrared spectroscopic capability, which has 

resulted in an increasingly improving picture of the 

evolution of galaxies over the life of the universe. Herschel launched on May 14, 2009 and is providing our 

first large-scale look at the high-redshift universe in 

the submillimeter. The James Webb Space Telescope, 

scheduled to be launched in 2014, will provide a window into the epoch of galaxy formation to clarify the 

processes that produced the present universe. 

More than half the power of highluminosity galaxies is emitted in the 

rest-frame far-infrared, so far-infrared and 

submillimeter imaging and spectroscopy 

are required for a full understanding of 

the physics of these systems.

Future far-infrared and millimeter facilities will play an 

important role in clarifying and extending this work. 

More than half the power of high-luminosity galaxies 

is emitted in the rest-frame far-infrared, so far-infrared 

and submillimeter imaging and spectroscopy are required for a full understanding of the physics of these 

systems. The next steps in NASA’s profoundly successful science program are currently being developed and 

the priorities for the space missions, supplemented by 

suborbital missions, being established. 

SOFIA, having just recently completed its first opendoor flights, will be a key facility for imaging and spectroscopic follow-up of Spitzer and Herschel discover-
35

Astrophysics Science Division: Research and Missions

30m radio telescope in Pico Veleta, Spain, where it has 

already provided a great advance in our understanding of the technology and produced new astronomical measurements. This instrument is in the process of 

being made available to the worldwide astronomical 

community.

We have also produced the detector subsystem for the 

ZEUS spectrometer, an experimental instrument at 

the Caltech Submillimeter Observatory. Its relatively 

modest detector array (only 32 pixels) has nonetheless 

been able to make the first detections of redshifted line 

emission from galaxies halfway across the universe, 

near the epoch of peak star formation. 

Recently, work has begun on a new generation of detector technology and instrument concepts. Based on 

superconducting resonators and kinetic inductance 

detection, this technology may enable entire instruments to be built on a single silicon wafer.

Variable-delay Polarization Modulators for 

Exploring Inflation

The study of the cosmic microwave background 

(CMB) with missions such as COBE and WMAP has 

proven to be one of the most valuable tools in decoding the physics of the early universe. To explain the 

observed flatness and the origin of structure, it has 

been hypothesized that the universe underwent an 

early epoch of exponential expansion known as inflaies. Measurements of the polarization of the CMB 

promise to allow us to distinguish among models of 

the first instants of our universe. Further in the future, 

great advances in sensitivity, angular resolution, and 

overall instrument capability will be realized by large 

cryogenic telescopes in space, such as SPICA, CALISTO or SAFIR, SPIRIT, and SPECS. High-performance far-infrared detector arrays are required for all 

this high- priority work. 

The far-IR instrument development group in ASD 

(Benford, Chuss, Fixsen, Kogut, Moseley, Staguhn, 

Voellmer, Wollack) have ongoing research projects to 

develop, implement, and field these detector arrays. 

Our large-format filled arrays will enable major advances in space-borne, sub-orbital, and ground-based 

infrared, far-infrared, and sub-millimeter instrumentation. Precision on-chip polarimeter detectors will 

enable sensitive measurement of the very slightly polarized signal from the CMB, in concert with a capable 

polarization modulator also developed in ASD. A balloon-borne experiment to measure the CMB polarization signal, PIPER, has recently been started and will 

use both the modulator and the large-format arrays.

One recent success has been the completion of a long 

wavelength (2 mm) camera based on a 128-element 

close-packed planar bolometer array that uses novel 

superconducting thermistors read out by SQUID 

multiplexers. This instrument, named GISMO, has 

been in use for astronomical observations at the IRAM 

Left: A VPM consists of a polarizing grid placed parallel to and in front of a moving mirror. By varying the 

grid-mirror separation, a variable phase delay between two orthogonal polarizations is introduced. This delay 

sets the mapping between the output and input polarization states. Center: The Hertz VPM. This VPM 

provided a demonstration of the technology in the submillimeter regime. Right: A prototype large polarizing 

grid is shown, a required milestone on the path to constructing VPMs large enough to position at the front 

of CMB polarimeters. 

Input Port Output Port

Movable Mirror

Phase delay

Polarizing Grid

Piezoelectric

Motor

Grid Flattener

Grid/Mirror

15 cm

50 cm
Astrophysics Science Division: Research and Missions

36

in the Laboratory, are a key technology on the path to 

an eventual CMBpol Inflation Probe mission.

MKID Detectors for Submillimeter 

Astronomy

Ed Wollack and collaborators are actively pursuing the 

extension of Microwave Kinetic Inductance Detectors 

(MKIDs) technology to the 38–400 μm spectral regions via a novel detector concept. Of the high-performance detector-array technologies currently being 

developed, the MKIDs may have the greatest promise 

for scaling to very large arrays (~105 detectors). Such 

arrays can provide high quantum efficiency and can be 

designed to provide background-limited performance 

over a wide range of incident powers, making them 

candidates for a wide range of instruments—from 

suborbital imagers to spaceborne spectrometers. 

Such large-format detector technologies are much 

needed in this important spectral region. Many of 

the primary diagnostics of a large range of galactic 

processes require observations in this spectral range. 

The far-infrared dust emission from normal and ultraluminous galaxies peaks in this spectral range, and its 

measurements are essential for understanding the energy production mechanisms and processes in the galaxies. Fine-structure lines of O III, NIII, O I, C I, and 

tion. If inflation occurred, it is expected to have left a 

small, polarized signature on the CMB. Measurement 

of such a signal would provide direct evidence for this 

inflationary epoch, along with a means by which to 

measure the physics of the first 10–32 second of the universe. 

Polarization modulation provides a means for extracting the small polarized signal from inflation from the 

large unpolarized CMB. To this end, variable-delay 

polarization modulators (VPMs) are being developed 

for a space-based instrument to measure the polarization of the CMB by David Chuss, Edward Wollack, 

Harvey Moseley, Gary Hinshaw, and George Voellmer 

in the ASD Observational Cosmology Lab. These 

modulators consist of a polarizing grid placed parallel 

to and in front of a movable mirror. By varying the 

grid-mirror separation, the phase between two orthogonal linear polarizations is also varied. This leads to a 

modulation of a single linear Stokes parameter with 

little contamination from the instrument. 

VPMs are potentially well-suited for a space mission 

because they avoid the use of dielectrics that require 

complex antireflection coatings. The modulation motion can be accomplished using small linear motions 

that can be done with reliable frictionless flexures. 

In addition, VPMs can be constructed large enough 

to cover the primary aperture of a telescope. This is 

advantageous in that it allows the modulation to be 

encoded on the signal before it can be contaminated 

by the instrument. In addition, the symmetry of the 

VPM modulation can be employed to reduce systematic errors, another key property of an eventual successful CMB polarimeter. 

Prototype VPMs have been constructed for use with 

the Hertz submillimeter polarimeter. These have been 

demonstrated at the Submillimeter Telescope Observatory in Arizona. The team is currently working on 

second generation VPMs for use in the Primordial 

Inflation Polarization Explorer (PIPER), a balloonborne CMB polarization experiment (PI, Kogut). The 

VPMs for PIPER will operate at 1.5 K, and therefore 

much of the current effort in design and fabrication 

involves challenges associated with these low operating 

temperatures that are similar to those for a space mission. The VPMs, along with detectors being developed 

A linear-array MKID test structure fabricated by 

the GSFC Device Development Laboratory.
37

Astrophysics Science Division: Research and Missions

N II fall in this spectral range. These lines can provide 

high-quality measurements of elemental abundances 

and physical conditions in the emitting regions. Many 

excited states of molecules, such as CO, are seen in 

this spectral range, and provide the capability to probe 

physical conditions in hot molecular clouds. Low-lying transitions of hydrides in this spectral region can 

probe cores of cooling clouds, providing information 

on star-formation processes. The goal is to produce 

detectors which will permit the use of these powerful 

diagnostic tools in future missions.

Presently, MKID detectors employ a resonant tank circuit made from a superconducting transmission line. 

Its quality factor, Q, and central frequency are read 

out using a microwave reflectometer. Millimeter-wave 

radiation is coupled into the device from an antenna, 

where it breaks Cooper pairs in the superconductor. 

This results in a change in the kinetic inductance of 

the microwave circuit, causing a change in the frequency and Q of the circuit. This technique works 

well at frequencies where the radiation can be coupled 

into the device using antennas and superconducting 

transmission lines. 

At frequencies above the superconducting gap of Nb, 

quality transmission lines are difficult to produce, so 

a different approach must be adopted. To achieve the 

desired sensor performance in the desired band, we 

modify this scheme by choosing the resonator metallization geometry and material properties consistent 

with its necessary roles in absorption of the incident 

wave and readout of the detector signal. The incoming light, with photon energy much greater than the 

superconducting gap, interacts with the spiral microwave transmission line. 

In the approach under development, the meander is 

chosen to have a surface-impedance and filling factor 

such that it presents the optimal matching impedance 

to the incoming wave, about 157 W per square. When 

the optical power is absorbed, it excites quasiparticles 

in the superconducting spiral, modifying the kinetic 

inductance of the line. The transmission line is configured as a l/2 stepped impedance resonator, designed 

to have a resonant frequency of ~1 GHz. The Q of 

the unilluminated resonator can be controlled by appropriate selection of the coupling Q to the transmission line. The device is optimized for a particular application by choosing the unloaded Q to be equal to 

the Q caused by quasiparticle dissipation at maximum 

power. The density of quasiparticles is a measure of 

our signal, and is sensed by the change in frequency 

and Q of the readout resonator.

Pending successful laboratory demonstration of 

the devices, a test of an array will be conducted in a 

350μm imager at the Caltech Submillimeter Observatory (CSO). This collaborative effort is led by Edward 

Wollack and includes S. Harvey Moseley (ASD) and 

Ari Brown, Wen-Ting Hsieh, Thomas Stevenson, and 

Kongpop U-yen of Goddard’s Engineering Directorate, and Professor Jonas Zmudizian of Caltech. 

Technology Development for Space-Based 

Imaging Interferometers

Dr. Kenneth Carpenter is coordinating the development of various technologies needed to enable large 

baseline, space-based imaging interferometers. These 

include:

1) the GSFC Fizeau Interferometer Testbed (FIT), 

a ground-based experiment to develop closed-loop, 

nanometer-level optical control of a many-element 

sparse array;

This sketch shows the sensor topology under study. 

Photons with energy greater than the gap energy 

are absorbed in the meander. The quasiparticle 

excitations change the center frequency and Q of 

the microwave resonator.
Astrophysics Science Division: Research and Missions

38

and synthetic-imaging maneuvers for sparse arrays. 

The primary goals of these programs are to mature the 

command and control algorithms required to enable 

formation-flying sparse-aperture/interferometric imaging missions. These systems must collectively operate over ~12 orders of magnitude, from the nanometer to the kilometer scale, and will therefore consist 

of “staged-control” algorithms operating in smaller, 

overlapping regimes but operating cooperatively over 

the full dynamic range. 

Kenneth Carpenter is the PI of the FIT effort and 

key Co-I’s include Richard Lyon (GSFC), and David 

Mozurkewich (Seabrook Engineering). The GSFClocated FIT is developing and demonstrating closed2) the MIT Synchronized Position Hold Engage Reorient Experimental Satellites (SPHERES) experiment, which uses hardware on ground-based flat-floor 

facilities (2-D) and in space (3-D) inside the International Space Station (ISS), to test centimeter-level 

Precision Formation Flying (PFF) algorithms; and

3) the GSFC Formation Flying Testbed (FFTB), a 

hardware-in-the-loop simulation facility that includes 

a simulated deployment of array spacecraft and the 

multi-stage acquisition of target light the individual 

mirrors by the beam-combiner. 

GSFC is also supporting an MIT SBIR Program utilizing the SPHERES to further develop formation-flying 

Top left: FIT Phase 1 at GSFC, with baffles removed for clarity. Top right: FIT Phase 2 array plate in assembly, 

with 11 of 18 mirrors/actuators installed. Bottom left: MIT SPHERES on the MSFC Flat Floor. Bottom Right: 

MIT SPHERES flying inside the International Space Station.
39

Astrophysics Science Division: Research and Missions

loop control, utilizing feedback from the science data, 

of the tip, tilt, piston, and translation of mirrors in a 

sparse array, and of the overall system to keep beams in 

phase and to optimize imaging. 

Dave Miller (MIT) leads the experiments with the 

MIT SPHERES to address constellation-wide sensing 

and control of the formation-flying spacecraft. This 

program is developing and demonstrating specific algorithms for autonomous, precision formation-flying 

and efficient synthetic-imaging maneuvers of an array 

of spacecraft. 

Eric Stoneking (GSFC/Engineering) has performed 

the most recent FFTB experiments. The end goal of 

all of this research and development is the production 

of a single system that will provide staged-control over 

the full dynamic range needed to enable these missions. While the detailed design of these experiments 

are based on the Stellar Imager (SI) mission, the technologies being advanced will help enable numerous 

additional missions being considered by NASA for 

flight, including the Space Infrared Interferometric 

Telescope (SPIRIT), Sub-Millimeter Probe of the 

Evolution of Cosmic Structure (SPECS), Life Finder 

(LF), Black Hole Imager (BHI/MAXIM), and Planet 

Imager (PI), as well as smaller precursor missions, such 

as the Fourier Kelvin Stellar Interferometer (FKSI), 

SI Pathfinder, selected Exo-Planet Probes, and ESA’s 

Pegase. Please see hires.gsfc.nasa.gov/si for additional 

information.

Wide-field Imaging Interferometry Testbed

Leisawitz and Rinehart are developing a broadly-applicable technique for wide field-of-view “double Fourier” (spatial and spectral) interferometry and evaluating 

its practical limitations. The Space Infrared Interferometric Telescope (SPIRIT; see the Mission Concepts 

section) could employ this technique—an analog to 

integral field spectroscopy—to image stars, planetary 

systems, and galaxies in the far-IR at 100x better angular resolution than the Spitzer Space Telescope while 

simultaneously providing information-rich spectra.

In 2009, the Wide-field Imaging Interferometry Testbed was used to collect a vast amount of high-quality 

interferometric data, an optical model of the testbed 

was refined and used to generate representative synthetic interferograms, and a wide-field spatial-spectral 

image-construction algorithm was further developed. 

A variety of spatial-spectral test scenes were observed 

in the lab, in most cases with the full u-v plane coverage required for high-fidelity image reconstruction. A 

new GSFC IRAD project will enable the replication 

of a NIST prototype hyperspectral scene generator. 

When ready, this device will produce complex, astrophysically realistic test scenes for observation in the 

lab. Co-op student Evan Sinukoff (McMaster University) gained proficiency in tuning and running the optical model, and model interferograms were found to 

be in excellent agreement with those observed. 

A new support structure for the optical cavity 

and thermal shields was designed by students 

and installed in late 2009 after the move to the 

Exploration Sciences Building.

The Wide-field Imaging Interferometry Testbed 

is functionally equivalent to the Space Infrared 

Interferometric Telescope, SPIRIT. The testbed, 

a high-fidelity model of the testbed, and new 

algorithms for spatial-spectral image construction, 

provide vital practical experience with the widefield double-Fourier interferometric technique to 

be used on SPIRIT
Astrophysics Science Division: Research and Missions

40

known as Time Delay Interferometry (TDI) to reduce 

the effects of laser frequency noise, it will still be necessary to actively stabilize the laser frequency.

One option for stabilizing the LISA lasers is to use 

the long arms of the constellation as a frequency reference, a technique known as arm-locking. Together 

with controls engineer Peiman Maghami (Code 591), 

Thorpe and Livas are studying arm-locking through 

frequency and time-domain simulations. By applying the techniques of optimal control theory to the 

problem of arm-locking, they have developed an approach that is less complex than the current baseline 

technique but with similar performance.

Another technique for stabilizing the LISA lasers is 

to use resonant optical cavities, a method commonly 

used in ground-based laboratories. The GSFC group 

has been developing optical-cavity-based stabilization 

systems for LISA for several years and has demonstrated that their performance exceeds the LISA requirements. Recently Livas, Numata, and Thorpe developed a modification to the standard optical-cavity 

technique that allows the stabilized laser to be tuned to 

any desired frequency without significantly degrading 

the stability. This work, which is the subject of a patent 

application, allows cavity stabilization to be combined 

with arm-locking, further increasing the performance 

margin for LISA.

Optical Assembly Articulation Mechanism (OATM) 

Testing. The LISA mission consists of a triangular 

Funding support for this research comes from the 

ROSES APRA program. The period of performance 

runs through FY11, by which time wide-field imaging 

interferometry will have matured to TRL 6.

Technology Development for LISA

Demonstrating technology readiness is critical to the 

success of the LISA mission. Scientists in the Gravitational Wave Astrophysics Laboratory, including 

Tuck Stebbins, Jeff Livas, Stephen Merkowitz, Jordan 

Camp, Kenji Numata, Felipe Guzman, and Ira Thorpe, are leading efforts to develop a number of technologies critical to LISA.

In addition to mitigating risks for LISA, these activities provided an opportunity for students to do cutting 

edge research. In 2009, several undergraduate students 

were involved in these activities including Chad Healy 

(USNA), Jeremiah Noordhoek (MIT), Kyle Norman 

(CU Boulder), Scott Smedile (VA Tech), and Wataru 

Kokuyama (U. Tokyo).

Laser Frequency Stabilization. LISA will use laser interferometry to monitor the distance between freelyfloating test masses on spacecraft that are separated 

by five million kilometers. This measurement must be 

made with a precision on the order of 10pm (1pm = 

10-12 m) so that the effects of gravitational waves can 

be measured. A stable laser wavelength (or frequency) 

is critical to achieving this accuracy. Although LISA 

will employ a sophisticated post-processing technique 

The inch-worm actuator was installed into the 

custom test apparatus in late 2009.

Summer student Kyle Norman uses a camera to 

inspect a bond during construction of the silicon 

carbide telescope structure.
41

Astrophysics Science Division: Research and Missions

constellation of three spacecraft, with interferometric 

links along each side of the triangle. As the spacecraft 

evolve in their orbits, the angles between pairs of arms 

vary slightly. A mechanism is needed to compensate 

for this variation and ensure that the LISA optical assembly is properly pointed at its distant target. The 

combination of high precision and large dynamic 

range is challenging for typical actuators. However, 

a device known as a piezoelectric inch-worm is wellsuited for such an application. GSFC has identified 

and procured an inch-worm that could meet the LISA 

requirements. Merkowitz and Thorpe, together with 

contract and civil-servant engineering support, are developing a test apparatus to evaluate the inch-worm. 

Using capacitive and interferometric sensing, the precision and stability of the inch-worm will be evaluated 

over its entire dynamic range. The test bed construction is nearly complete and a test campaign is expected 

to begin in early 2010. 

Telescope Structure Stability: The LISA telescope is 

used to increase the light-transfer efficiency between 

distant spacecraft. Since it lies in the interferometric 

path, it is critical that the optical path length through 

the telescope remain stable at the picometer level. Standard athermal design methods must be modified due 

to the presence of a large axial temperature gradient, 

since the secondary mirror looks at cold space while 

the primary is near the main optical bench, which is at 

room temperature. There is a smaller transverse temperature gradient as well. 

Livas, together with engineering support from GSFC 

and construction and testing support from the University of Florida, has developed a prototype metering structure of silicon carbide that will be used to 

evaluate the material for potential use in the LISA 

telescope. While not a true telescope in the sense that 

it does not focus light, the prototype is structurally 

similar to a telescope: four long legs attached to a large 

disk (the “primary”) support a smaller disk (the “secondary”). The six components of the telescope were 

manufactured individually and then bonded together 

using hydroxide-catalysis bonding. The structure will 

be tested in a thermal vacuum chamber at the University of Florida to determine how much the structure 

changes dimensionally as it is cooled to the operating temperature and gradient, and then monitored to 

check the long-term stability with femptometer-level 

accuracy. Testing is expected to begin in the spring of 

2010.

Fiber laser development. The LISA laser requires a 

single-longitudinal-mode output with high intensity 

The completed silicon carbide telescope structure. 

A white cloth visible on the primary plate protect 

the optics mounting pads from scratches and dust.

Fiber lasers such as this one developed at GSFC 

could be an alternative to commercial NPROs for 

the LISA seed lasers.
Astrophysics Science Division: Research and Missions

42

and frequency stability. Fiber laser/amplifier technologies have made great advances over the last decades 

and have some advantages over traditional bulk-optics-based lasers and amplifiers. 

Numata and Camp, together with technical support 

from the GSFC laser and electro-optics branch, have 

developed a ytterbium-fiber-ring laser. The performance of the fiber laser is comparable to commercial 

Non-Planar Ring Oscillator (NPRO), which has been 

traditionally used in low-noise applications. The fiber 

laser offers alignment- and magnet-free operations, 

rapid coupling into a fiber amplifier, and a spatially 

cleaned output.

Space qualification testing of the fiber components is 

expected to begin in the spring of 2010. It will include 

radiation hardness, outgas, thermal cycling, and vibration tests. This work is in cooperation with Lucent 

Government Solutions (LGS), which is performing 

thermal cycling tests of fiber amplifiers for LISA. In 

addition, Numata and Camp are investigating alternative oscillator configurations at several industrial vendors. These include the use of lasers based on short, 

high-gain phosphate glass fibers, and external cavity 

waveguides.

Absolute frequency reference. The heterodyne interferometry employed by LISA relies on the ability to match the absolute frequencies of the lasers on 

each spacecraft to within tens of megahertz. Numata, 

Camp, and Kokuyama have developed a reliable heterodyne acquisition system based on an iodine cell. 

They have demonstrated that two lasers can be tuned 

to a known absolute frequency within ~10 MHz accuracy using a very simple setup.

Three-Dimensional Track Imager Detector for 

Gamma-ray and Neutron Imaging

The development of the Three-Dimensional Track 

Imager (3-DTI) is motivated by the technology requirements for a future gamma-ray telescope that will 

provide optimum angular resolution over the energy 

range from ~5–500 MeV and for imaging of fast neutrons, En

 > 0.1 MeV, from passive and active interrogation of special nuclear materials (SNM). In these 

applications, the direction and energy (and polarization of gammas) of the incident neutral particles is determined from the three-dimensional momenta of the 

charged interaction by-products. 

Stanley Hunter, with Georgia de  Nolfo, Seunghee 

Son, Jason Link, and Michael Dion, are developing 

the 3-DTI for high-angular-resolution gamma-ray 

astronomy and neutron imaging. The 3-DTI is a 

large-volume time-projection chamber (TPC) with 

two-dimensional micro-well detector (MWD) readout. Relative time of arrival of the ionization charge 

provides the third spatial coordinate. Each well of the 

MWD, 200 mm diameter on 400 mm centers, is a gas 

proportional counter which allows gas gain in excess 

of 104

. Negative ion drift is utilized to reduce the drift 

The 10 × 10 × 15 cm3 NIC prototype and liquid 

scintillator neutron monitor at the NSWC 

Positive Ion Accelerator Facility. Neutrons were 

symmetrically scattered from the first scintillator 

into the second scintillator and the NIC.

A simple iodine wavemeter based on a frequencydoubling waveguide and a fixed-pressure short 

iodine cell aids in heterodyne acquisition. 
43

Astrophysics Science Division: Research and Missions

velocity and diffusion allowing for the large TPC volume. This team’s accomplishments this year include:

1) Complete analysis of the Neutron Imaging Camera 

(NIC) data taken at the NSWC Positive Ion Accelerator Facility (PIAF). This analysis, including measured 

neutron angular resolution, q68 ~8 deg at 2 MeV, were 

presented by Dr. Son at the APS meeting in Denver 

and by Dr. de Nolfo at the IEEE meeting in Massachusetts. 

These NIC results were obtained using helium-3, the 

traditional neutron-detection gas. The availability of 

helium-3, however, has recently become very limited 

with little or no improvement foreseen. This forced 

us to re-examine the operation of the NIC. Extensive calculations, corroborated with GEANT4 by Dr. 

de Nolfo and GARFIELD simulations by Dr. Dion, 

indicate that the NIC performance can be realized 

using multiple proton scattering in a proton rich gas 

such as methane or ethane. Michael Shields, a summer intern, contributed to these calculations. Ongoing MWD testing has demonstrated viable operation 

in methane. This work was summarized in an internal 

report and included in a detailed brief to DTRA in 

September 2009. 

2) The in-house laser micro-machining facility was 

re-established, including upgrades to the computer 

interface and control software, and addition of LabView image processing software. Improvements in our 

micro-machining techniques have resulted in fabrication of high-gain 10 × 10 cm2 MWDs to track minimum ionizing electrons resulting from photon interactions in the TPC gas. The next goal is to produce 

30 × 30 cm2

 MWDs.

3) The electrical and mechanical design of a 

30  ×  30  ×  30  cm3 3-DTI prototype has been completed. This prototype will require 1,536 channels of 

charge amplifier and transient digitizer. Two versions 

of an ASIC with sixteen channels of charge and shaping amplifiers, optimized for negative and positive 

signals, have been fabricated and are being tested. A 

new readout method has been devised and incorporated into the design of the transient digitizers. This 

“streaming mode readout” eliminates essentially all 

dead-time in the 3-DTI by continuously sampling the 

output and sending only those samples above threshold to the next level of data processing, i.e., hardware 

zero-suppression. The front-end ASIC board, TD 

concentrator board, and the power distribution board 

make up the remainder of the electronics. The design 

of these boards has started. 

4) A second 10 × 10 cm2

 test chamber was built. This 

chamber also provide a means of testing MWDs up to 

30 × 30 cm2 using the existing 10 cm electronics. 

S. Hunter and collaborators submitted the White Paper “Medium Energy Gamma-Ray Astrophysics” for 

consideration to the Astro2010, Astronomy and Astrophysics Decadal Survey.

Photon Counter Detector Development

Work is ongoing in the Exoplanets and Stellar Astrophysics Lab to develop photon-counting detectors for 

Gas gain vs. anode/cathode voltage performance 

of second-generation GSFC MWDs produced 

in 2009 is similar, and in some cases, exceeds the 

performance of the first-generation MWDs (blue 

line). The gain measurement was done using a 

collimated 55Fe source, in P-10 (90% Ar, 10% CH4) 

gas at 1 atmosphere. The maximum gain is limited 

by breakdown. Orange data points are in pure CH4 

gas. 
Astrophysics Science Division: Research and Missions

44

space in the UV, visible and near-IR by Woodgate, 

Kimble, Rauscher, Norton, and Hilton.

For the UV, a new class of photocathodes are under 

development with higher QEs than were available in 

the Hubble, FUSE, and GALEX era, based on new 

ternary materials becoming available such as p-doped 

AlGaN and MgZnO, in both planar and nano-wire 

forms. By cesiating GaN, QEs of 50–60% at 180 nm, 

a factor ~6 higher than flown on HST/STIS, and 

65–68% at 122nm, have been obtained. A GaN photocathode has been transferred into a diode tube with 

the QE stable for four years, and into an EBCCD imaging tube in collaboration with Rutgers University, 

and larger format EBCMOS tubes are being designed. 

Work continues via ROSES/APRA funding to extend 

the wavelength range and to obtain higher QEs and 

compatibility with microchannel plates (MCPs). SBIR 

programs funded by NASA are also developing silicon 

MCPs with AlGaN photocathodes. Woodgate, along 

with GSFC engineering, university, NIST, and commercial partners, plans to build these photocathodes 

into EBCCD and EBCMOS and MCP detectors.

In the visible, photon-counting EMCCDs are being 

tested for use in future space spectrographs for faint 

objects such as exoplanet atmospheres, and will use 

fast controllers to reduce Clock Induced Charge to extend the useful dynamic range of the photon-counting 

regime. A 1k ×1k EMCCD will be used in a groundbased integral field spectrograph.

In the Near-IR the use of InGaAs photocathodes in 

EBCCD detectors are being investigated, including 

the extension of useful external QE at cold temperatures for long exposures via an SBIR program.
45

Astrophysics Science Division: Research and Missions

V. Projects

Projects in Operation

The Fermi Gamma-ray Space Telescope

GSFC personnel are extremely active in all aspects 

of Fermi (formerly the Gamma-ray Large Area Space 

Telescope, GLAST), both at the mission level and 

within the instrument teams. Highlighted here is 

GSFC’s role in Fermi’s Large Area telescope (LAT), 

some of the current LAT activities, and some of the 

mission-level work, including the Science Support 

Center.

Fermi-LAT First Year Science

Current Fermi LAT Activities. The LAT Principal 

Investigator is P. F. Michelson (Stanford). Within the 

LAT team, GSFC members played key roles throughout the first year of science observations. Presently, the 

major roles include the following: N. Gehrels (Senior 

Scientist Advisory Committee [SSAC] chair and Publication Board [PB] member); A. Harding (Galactic 

Sources Group coordinator), E. Hays (Spectral Analysis Study group lead), J. McEnery (SSAC, PB, GRB 

commissioner); A. Moiseev (active in electron analysis); D. J. Thompson (Multiwavelength Coordinator, 

Catalog Group coordinator, SSAC). Bonnell, Corbet, 

Davis, Ferrara, Hirayama, Hunter, Sambruna, Shrader, and Stecker are affiliated-scientist members of the 

LAT team. 

GSFC scientists have made major contributions to the 

first year of LAT science results. McEnery focuses on 

the study of high-energy gamma-ray emission from 

gamma-ray bursts, especially the temporally extended 

component recently discovered by Fermi to be present 

in all high-energy- emitting GRBs. Alice Harding plays 

a key role in data analysis and theoretical interpretation of the growing Fermi pulsar populations. Hays, 

in collaboration with C. C. Cheung (former GSFC 

postdoc) conducts searches for unassociated gammaray transients near the Galactic Plane and pursues 

multiwavelength follow-up to determine their origin. 

J. Racusin is pursuing Fermi-Swift overlap studies of 

GRBs. Corbet has played a key role in the detection of 

periodicity in gamma-ray binaries such as LS +61 303, 

LS 5039, and Cygnus X-3. Ferrara participates in the 

identification of pulsar candidates and is leading work 

to characterize the current unassociated gamma-ray 

source population.

Goddard plays an important role in a very broad variety of LAT activities through a number of students and 

postdocs that collaborate with the international team. 

The current PhD students are T. Johnson, W. McConville, E. Winter, M. DeCesar, S. Zhu, and J. Cohen (all 

at University of Maryland), and the post-docs are O. 

Celik, and V. Vasileiou. McConville has served as both 

a data quality monitor and a gamma-ray skywatcher/

flare advocate. Vasileiou and Winter contribute burst 

advocate shifts and the analysis of GRBs with the LAT 

data. In addition, Vasileiou has developed an innovative method for characterizing LAT background rates 

during gamma-ray burst observations. Zhu is studying 

possible improvements to onboard gamma-ray burst 

detection that may enhance the ability of the LAT 

to respond to high-energy activity and trigger critical multiwavelength follow-up observations. McConville analyzes the temporal and spatial properties of 

gamma-ray emission of radio galaxies, such as NGC 

1275 and Cen A. Johnson and Celik have conducted 

high-precision studies of the dependence of gammaray emission from bright pulsars, such as Vela, Crab, 

and Geminga, depends on rotational phase. Johnson is 

also active in characterizing the spectra of gamma-ray 

millisecond pulsars for use in deciphering the underlying emission mechanism of this growing gamma-ray 

source class. DeCesar explores the pulsar lightcurves 

from gamma rays to radio as a tool for probing emission zones. Cohen is beginning work to characterize 

the morphology and spectra of the unpulsed, nebular 

component present in some gamma-ray pulsars.

Fermi Mission and SSC. The Fermi mission is managed at Goddard, and the Mission Operations Center 

(MOC) is located here. The MOC is staffed by an outstanding Flight Operations Team and is supported by 

a small sustaining engineering group. McEnery is the 

Project Scientist, and Hays, Thompson, and Gehrels 

are Deputy Project Scientists. The Fermi Science Support Center (FSSC) is also located at Goddard and 

is led by Chris Shrader. The FSSC functions can be 

divided into three main roles.

1) The mission planning and operations branch compiles and optimizes the Fermi observation plan (including responding to and evaluating Target of Op-
Astrophysics Science Division: Research and Missions

46

The observation planning, instrument monitoring, 

and calibration updates are carried out with the parttime contributions of an experienced team (including 

Keith Jahoda, Craig Markwardt, and Nikolai Shaposhnikov at Goddard). Improvements in background 

determination and response matrices continue to be 

made.

The Science Operations Center (SOC), with Frank 

Marshall as director, assisted by Robin Corbet as Science Operations Facility manager, and the GSFC Mission Operations group have worked together to continue to automate operations and reduce manpower 

and expenditures, while preserving RXTE’s ability to 

accommodate new information about targets of opportunity (TOOs) (implemented by SOF personnel 

Evan Smith and Divya Pereira). RXTE’s most-used 

follow-up capability is currently for time-scales of 

1–2 days. It is possible to have follow-up observations within hours for a select subset of requests, but 

transients that harbor millisecond pulsars, active periods of magnetars, the lifecycles of galactic black hole 

transients, and, of course, the active periods of blazars 

require a response on the order of days that can be sustained for days to weeks. RXTE remains the mission 

that is requested to carry out these observations. 

RXTE is the only current X-ray 

observatory with the capability to 

routinely measure the millisecond spin 

periods of accreting neutron stars. 

The RXTE project has submitted proposals to each of 

NASA’s Senior Reviews of the Astrophysics Operating Missions since 1994. The 2006 review confirmed 

RXTE’s operations through the 2008 review, by which 

time the project had developed a program to extend 

operations through February 2009. The 2008 review 

concluded that funds were not available for further 

funding of the longest operating of the competed astrophysics missions. However, continued reductions 

in operating costs, combined with additional funds 

and guidance from NASA HQ, are allowing the mission to operate through September 2010. The possibility of extension of RXTE’s mission for an additional 

portunity requests). This branch runs weekly planning 

meetings to coordinate observatory operations across 

all mission elements.

2) The analysis software and databases branch developed the high-level analysis software in partnership 

with the LAT and Gamma-ray Burst Monitor (GBM) 

instrument teams. The FSSC serves data to the community, working with the HEASARC to ensure that 

the analysis tools and data formats conform to standards in high-energy astrophysics. High-level LAT 

data and all GBM data have been hosted since the 

beginning of science operations; the portal to the lowlevel LAT came online in August 2009; and the first 

catalog provided by the LAT is hosted by the FSSC. 

3) The user-support branch of the FSSC is responsible 

for running the Fermi guest investigator program, developing proposal preparation tools, providing documentation, running workshops, and answering questions via an electronic helpdesk. Cycles 1 and 2 were 

both very successful, and the Cycle 3 proposal deadline is February 5, 2010. The FSSC hosted a series of 

highly successful data analysis workshops during late 

2009 to aid guest investigators in using the tools and 

developing proposals.

Supporting all three branches of the FSSC is a group 

of talented programmers and software engineers who 

build and maintain the software infrastructure and 

web pages. All the mission elements are functioning 

together efficiently and seamlessly.

The Rossi X-ray Timing Explorer

The Rossi X-ray Timing Explorer (RXTE) celebrated 

its 14th birthday on Dec. 30, 2009, and began its 

14th cycle of observations. Of currently operating 

NASA missions, only Hubble has been in orbit longer. 

Jean Swank is the Project Scientist and Tod Strohmayer became the Deputy Project Scientist in 2006. In 

its long and productive history, RXTE is responsible 

for numerous discoveries resulting in three Rossi Prizes—to Strohmayer and Chakrabarty (2006), Kouveliotou and Thompson (2003), and Bradt and Swank 

(1999)—more than 90 PhD theses, and over 2,100 

refereed publications. 
47

Astrophysics Science Division: Research and Missions

year or two beyond that will be addressed by NASA’s 

2010 Senior Review, to which RXTE has been invited 

to submit a proposal. This will allow the torch of X-ray 

coverage of variable sources to be passed to other missions, such as the recently launched MAXI and the yet 

to be launched Astrosat.

RXTE is the only current X-ray observatory with the 

capability to routinely measure the millisecond spin 

periods of accreting neutron stars. Recent observations 

have led to the discovery of two more of these objects, 

including one, NGC 6440 X-2, that shows unusually short, faint, and frequent outbursts that are easily missed with current X-ray monitoring capabilities, 

suggesting that a sizeable population of similar objects 

may await discovery. A program of monitoring pulsar 

spin histories of magnetars has recently found sudden increases or glitches in their spin rates with exotic properties. In several cases, the frequency jumps 

up, but then more slowly recovers to a value less than 

the pre-glitch frequency. This is the first time such 

“negative recovery” glitches have been seen in magnetars (postdoctoral researcher Fotis Gavriil is involved 

with this work). Coverage of the QPO and spectra of 

multiple Galactic black holes—including the newly 

discovered sources XTE J1652-453 and XTE J1752-

223—allow the correlations to be related to fundamental properties of mass and spin (as by postdoctoral 

researcher Nikolai Shaposhnikov). RXTE’s observing 

flexibility is enabling it to support Fermi monitoring 

observations of blazars, such as the recent observing 

campaign studying active flaring in Mrk 421.

XMM-Newton Guest Observer Facility

ASD operates the U.S. XMM-Newton Guest Observer Facility (GOF). ESA allocates resources to support 

European XMM-Newton users, but looks to the U.S. 

GOF to provide support to the large U.S. community. 

GOF activities include facilitating the submission of 

GO proposals to ESA and the supplying of expertise, 

analysis software, documentation, new data products, 

and access to the data, including both the distribution 

of proprietary data to PIs and to the full public science 

archive. The GOF organizes the GO budget submission and review process and manages the distribution 

of awarded funds. 

A U.S. XMM-Newton Users Group under the chairmanship of Prof. Craig Sarazin (U. Virginia) provides community oversight of GOF activities. Steve 

Snowden is the NASA Project Scientist. The XMMNewton GOF works in conjunction with the GSFC 

GOFs of other high-energy astrophysics missions (e.g., 

RXTE, Integral, Fermi, Swift, and Suzaku) to lower 

costs and to ensure consistency in the areas of the budget proposal process, FITS tools, database structure, 

web pages, and archival access. Cost savings are leveraged by sharing resources, techniques, expertise, and 

reusing software. GOF activities cover a very wide 

range of endeavors in support of XMM-Newton and 

include (besides the activities mentioned above) development of software tools (ESAS, QuickSim, Xsim) 

and the updating of HEASARC multi-mission software (Browse, PIMMs, etc.). The GOF created and 

maintains the extensively used “ABC Guide” and “D 

Guide” for the analysis of XMM-Newton science data. 

The GOF has also supported the HEASARC HERA 

project which will provide an online multimission (including XMM-Newton) data analysis capability.

The GOF remains involved in the particle background 

calibration of the X-ray imagers and the cross-calibration between the XMM-Newton instruments and other X-ray observatories (e.g., Chandra, Suzaku, ASCA, 

XMM-Newton European Photon Imaging Camera 

(EPIC) image of the LMC2 – N132D region of 

the Large Magellanic Cloud. This backgroundsubtracted, exposure-corrected image was made 

possible by software developed by the GOF.
Astrophysics Science Division: Research and Missions

48

and ROSAT), which enhances the utility of multi-observatory data analysis. This has been a major activity 

over the last three years, with major XMM-Newton 

GOF participation in the International Astronomical 

Consortium for High Energy Calibration (IACHEC). 

It became clear, thanks to the efforts of the XMMNewton SOC at the European Space Astronomy Center (ESAC) and the GOF, that the XMM-Newton 

calibration has become very reliable and that direct 

comparison of Chandra and XMM-Newton results 

on clusters of galaxies revealed a previously unknown 

error in the Chandra calibration which has major implications for cosmology.

The GOF prepared and maintains the Optical Monitor (OM) source catalog (Kuntz et al. 2008, PASP, 

120, 740) to compliment the X-ray source catalog produced by the XMM-Newton Survey Science Centre 

(SSC). The database contains entries for every source 

detected in OM observations. The GOF worked with 

the STScI to make the OM catalog and data available 

through the Multimission Archive at Space Telescope 

(MAST), considerably increasing the data availability 

to optical astronomers.

The XMM-Newton archive at the GSFC GOF mirrors all public data in the ESA XMM-Newton Science 

Archive (XSA) at the SOC, as well as proprietary data 

for U.S. PIs. This mirroring of the data reduces the 

high data load at the European Space Operations Center site, and provides a much faster data-transfer rate 

within North America, as well as allowing use of the 

unique capabilities of the BROWSE database.

The GOF consists of Project Scientist Snowden, GOF 

scientists Lynne Valencic and Kip Kuntz, and about 

four other support personnel and programmers. The 

scientific return to the community is exceptionally 

high for such a lean staff.

Swift

Swift is a NASA Explorer mission, with international participation, that is designed to find gamma-ray 

bursts and study them over a wide range of wavelengths—from gamma-rays to optical light. It was 

launched in 2004 and is in its extended mission phase 

with re-entry no earlier than 2020. 

Gamma-ray bursts (GRBs) are the most luminous explosions in the universe since the Big Bang. They come 

randomly from all directions in the sky and last from a 

few milliseconds to a few hundred seconds. GRBs are 

believed to occur in the collapse of some massive stars 

into supernovae or when two neutron stars merge. The 

details of how such intense bursts of radiation are produced are still not well understood.

There are three telescopes onboard Swift. The Burst 

Alert Telescope is a coded-aperture gamma-ray detector that operates between 15 and 150 keV. It detects 

GRBs and rapidly localizes them to approximately 

two arcminutes. Immediately afterward—usually 

within one minute—the spacecraft slews to point its 

two narrow-field instruments at the burst. The X-Ray 

Telescope measures the 0.2–10 keV X-ray flux from 

the GRB’s afterglow and localizes the source to within 

two arcseconds. The Ultraviolet/Optical Telescope 

collects data between 1600 and 6000 Angstroms and 

provides a sub-arcsecond position for the burst. Swift 

distributes these positions for each GRB to other observatories within seconds of obtaining them.

By the end of 2009, more than 800 

refereed papers have been published that 

are based on Swift results. These Swift 

papers have a very high citation rate of 

around 19 per paper on average (more 

than 15,000 total).

In the five years since launch, Swift has detected and 

localized approximately 500 GRBs. Some of the mission’s key scientific accomplishments have been:

• Detecting the most distant known object in the 

universe, GRB 090423, with a redshift of 8.2. 

This burst occurred more than 13 billion years 

ago when the universe was only about 630 million years old.

• Observing GRB 080319B, a GRB with an afterglow that was bright enough to see with the naked 

eye from a dark site.

• Discovering more than 45 short and hard GRBs, 

about half with likely host identifications and/or 

redshift estimates. These observations provided 
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Astrophysics Science Division: Research and Missions

support for the theory that these bursts are due to 

the merging of binary neutron stars.

• Making metallicity measurements of star-forming 

regions at high redshift (z > 5) using GRBs.

• Discovering the X-ray flash from the shock breakout from the surface of a star during a supernova.

Swift is a powerful and versatile observatory to study 

transient sources and is increasingly being used for 

non-GRB science. To date, more than 1,400 Targets 

of Opportunity (TOOs) were performed as a result of 

requests from the community. Many of the TOOs are 

often made within a few hours after being requested. 

By the end of 2009, more than 800 refereed papers 

have been published that are based on Swift results. 

These Swift papers have a very high citation rate of 

around 19 per paper on average (more than 15,000 total). About half of all Swift papers are from non-GRB 

fields with an increasing fraction. A few examples include: performing multiwavelength observations of 

comets; stellar flares, CVs, and novae; obtaining ultraviolet light curves for more than 100 supernovae 

of all types; observing galactic transients and AGNs; 

performing a survey of nearby galaxies in the optical, 

UV, and X-rays; and undertaking the most sensitive 

all-sky, hard-X-ray survey yet performed.

Swift has been widely recognized as a ground-breaking 

mission. It was ranked first in the 2008 Senior Review. 

The PI Neil Gehrels and the Swift Team won the 2007 

Rossi Prize, the 2009 Muhlmann award of the Astronomical Society of the Pacific, and GRB 080319B 

(the naked-eye gamma-ray burst) was named one of 

the top ten science news stories of 2008 by the American Institute of Physics.

The Swift Guest Investigator Program adds an important component to the Swift research and includes 

both GRBs and non-GRB science. During the 2009 

Cycle 6, 169 proposals were received, requesting 

$4.8M in funds and 16.7 Ms total exposure time for 

1,244 targets. The oversubscription rate has grown to 

a factor of 4.4 for non-TOO proposals and the TOO 

category had an oversubscription factor of 6.1.

Suzaku (Astro-E2) 

Suzaku (Astro-E2) is the fifth in a series of Japanese 

X-ray astronomy satellites, launched by the Japan 

Aerospace Exploration Agency (JAXA) on July 10, 

2005. Like ASCA before it, Suzaku is a joint JapaneseU.S. mission, developed by the Institute of Space and 

Astronautical Science of JAXA (ISAS/JAXA) in collaboration with GSFC and many other institutions.

Suzaku’s scientific payload includes three co-aligned 

instruments, of which two are functional. The X-ray 

Imaging Spectrometer (XIS) consists of four imaging 

CCD cameras, three of which are front illuminated 

Ultraviolet mosaic image of M31 taken with Swift’s UVOT in filters uvw1 (192.8 nm), uvm2 (224.6 nm), 

and uvw2 (250 nm). The image shows a field of ~100 x 50 arcminutes.
Astrophysics Science Division: Research and Missions

50

(FI: energy range 0.4–12 keV) and one back illuminated (BI: energy range 0.2–12 keV). Each XIS is located at the focal plane of a dedicated X-ray telescope 

(XRT). One of the three FI chips was rendered inoperable by a micrometeorite impact in December 2006; 

a micrometeorite impact in June 2009 made a small 

portion of a second FI detector unusable. The second 

functional instrument is a non-imaging, collimated 

Hard X-ray Detector (HXD) sensitive in the 10–600 

keV band. The third instrument, the X-Ray Spectrometer (XRS), ceased operation shortly after launch due 

to a spacecraft design error. 

GSFC’s role includes supplying the XRTs and the XRS 

“insert” (detector, adiabatic demagnetization refrigerator, and LHe cooler), development of data-processing 

software, operation of the U.S. Guest Observer Facility (GOF), and administration of the U.S. Guest Observer (GO) Program. Rob Petre is the NASA Project 

Scientist, and Lorella Angelini is the Deputy Project 

Scientist. 

Suzaku has produced an abundance of data from 

a wide variety of cosmic X-ray sources. Key unique 

Suzaku observations include: measurement of cluster 

properties beyond their virial radius; broadband measurements of AGN revealing simultaneously complex 

absorption, a relativistically broadened Fe K line, and 

a reflection continuum to 20–40 keV; determination 

of the spin of Galactic black holes and the radius of accreting neutron stars using their relativistically broadened Fe line; and measurement of the spectrum of a 

substantial fraction of the AGN detected by Swift.

U.S. observers have access to 50 percent of the observing time (including 12 percent through joint Japan/

U.S. observations), as well as access to all archival 

data. In the third observing cycle (April 2008–March 

2009), Long Proposals (observing time > 300 ks) were 

introduced to the program. In the fourth observing 

cycle (April 2009–March 2010), key projects (observing time > 1Ms) were introduced. Four key projects 

were selected: extensive mapping of the Galactic center region; a comprehensive study of anomalous X-ray 

pulsars; a deep observation of Kepler’s SNR to characterize the explosion mechanism through measurements of modest-abundance metals; and a census of 

broad Fe lines in AGN. Also, joint Suzaku-Chandra 

observations are now available through the Chandra 

GO program.

Suzaku received a high ranking (fourth of nine missions) by the 2008 NASA Senior Review of operating 

missions. Funding is secure through FY 2011, and the 

opportunity exists to extend U.S. participation beyond 

that through a proposal to the 2010 Senior Review. 

The Suzaku GOF is responsible for processing and archiving the full mission data set and distribution of 

data to U.S. GOs; development and maintenance of 

proposal and observation planning tools and documentation; maintaining the calibration database; supporting proposal reviews; assisting GOs in analyzing 

data; and ensuring grant funds are distributed in a 

timely way. The GOF staff consists of three full-time 

scientists (Koji Mukai, Kenji Hamaguchi, Katja Pottschmidt) and one programmer, plus part-time support 

from HEASARC staff.

INTEGRAL

INTEGRAL, the INTErnational Gamma-Ray Astrophysics Laboratory, is an ESA mission with which 

NASA has partnered since its selection in 1995. It was 

launched in October 2002 and has now completed 

more than seven years of successful scientific operations. 

INTEGRAL carries two main instruments—the 

high-resolution gamma-ray spectrometer, SPI, and the 

high-angular-resolution gamma-ray imager, IBIS—as 

well as X-ray and optical monitors. Together, these 

instruments provide unprecedented spectral coverage 

from the optical to gamma-ray energies up to 10 MeV, 

as well as excellent imaging capabilities at hard X-ray 

and gamma-ray energies.

The scientific goals of the INTEGRAL mission are 

varied and far-reaching. The SPI instrument is a coded-mask germanium spectrometer with excellent energy resolution in the low-energy gamma-ray regime, 

from 20 keV to 8 MeV. It was designed to study, in 

detail, gamma-ray lines produced through a variety of 

processes. These include the decay of radioactive isotopes produced in supernovae and novae as well as the 

annihilation of positrons near the center of our Gal-
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Astrophysics Science Division: Research and Missions

axy. SPI can trace the production of these radioactive 

isotopes and positrons by mapping the locations and 

intensities of the resulting gamma-rays. These studies 

lead to a better understanding of the chemical evolution of the Galaxy, Galactic star-formation rates, and 

the inner workings of supernovae and novae.

The IBIS imager is a coded-mask gamma-ray telescope 

that operates between 15 keV and 10 MeV. The sensitivity and angular resolution of this telescope make 

it extremely useful for observing Galactic black hole 

and neutron-star binary systems as well as active galactic nuclei (AGN). To this end, a significant portion of 

the INTEGRAL observing time has been spent scanning the Galactic disk and Galactic Center region in 

an effort to monitor the known Galactic X-ray binary 

population and discover new sources. Studies of these 

binary systems give us a better understanding of the 

end products of stellar evolution.

In the seven years since launch, there have been numerous notable discoveries, including:

• Discovery that the hard x-ray/soft-gamma-ray 

emission from the Crab nebula/pulsar is highly 

polarized, suggesting that the high-energy electrons producing this emission are in a highly ordered structure near the pulsar.

• Discovery that the Galactic 511 keV emission due 

to positron annihilation is not symmetric about 

the Galactic Center. This has significant implications for determining which source(s) are producing these positrons.

• Observations of the gamma-ray lines from the decay of both 26Al and 60Fe in the Galaxy suggest 

that much of the 26Al is produced in core-collapse 

supernovae.

• Discovery of a large number of X-ray binary systems containing a supergiant companion. Among 

this class of objects, two subclasses have been 

identified: Systems with highly absorbed soft 

X-ray spectra and systems that exhibit very fast 

transient behavior. The hard X-ray sensitivity of 

IBIS and its monitoring observing program were 

instrumental for these discoveries.

Since launch, INTEGRAL has operated as an international observatory with observing time available 

to U.S. scientists. NASA has an INTEGRAL Guest 

Investigator Program that provides funding for U.S. 

scientists who were successful in obtaining observing 

time. In 2009, the INTEGRAL Guest Investigator 

Program has funded 12 observing programs for a total 

of $350,000. 

The U.S. INTEGRAL Guest Observer Facility maintains a copy of the full INTEGRAL public data archive and supports U.S. scientists with their data analysis. Neil Gehrels is the NASA INTEGRAL Project 

Scientist and Steve Sturner is the GOF Lead Scientist.

Hubble Space Telescope: SM4 and Wide Field 

Camera 3

SM4 a complete success, the long-awaited science 

begins

The year 2009 was utterly spectacular for Hubble. 

Servicing Mission 4 (SM4), the mission originally 

planned for 2002 but long delayed, finally got off the 

ground with the May 11 launch of Space Shuttle Atlantis and the STS-125 mission. The manifest was so 

densely packed with replacement and repair hardware 

that the official EVA timeline did not accommodate 

all the tasks. In a servicing tour de force made possible 

not only by the astronauts but also by the work of 

more than a thousand people at GSFC, JSC, STScI, 

and various contractor sites, Atlantis’s crew accomplished all tasks. The mission was jointly run out of 

JSC—responsible for the shuttle and its astronauts—

and GSFC, which controlled and operated Hubble 

during the mission. The result is a new telescope, one 

with scientific capabilities far beyond what it has ever 

possessed. The final chapter of Hubble science—the 

next five-plus years—promises to be truly remarkable.

Before SM4 there was only one working science instrument (two, if the astrometer Fine Guidance Sensor 

[FGS] is counted): the venerable Wide Field and Planetary Camera 2 (WFPC2). Now the Hubble science 

community has at least four (five with FGS) to utilize 

in their research: Wide Field Camera 3 (WFC3) and 

Cosmic Origins Spectrograph (COS)—both new—

and Space Telescope Imaging Spectrograph (STIS) 

and Advanced Camera for Surveys (ACS)—both repaired during SM4 in the first successful instrument 

surgeries in space. The Near Infrared and Multi-Object Spectrometer (NICMOS), which was not serviced 
Astrophysics Science Division: Research and Missions

52

All in the Hubble Project Science Office had important, well-defined roles in the run-up to and execution 

of SM4, with special emphasis on the instrument and 

instrument-repair development efforts, the prioritization of tasks (both scientific and engineering) for the 

mission, overall mission operations, and the development and interpretation of on-orbit functional tests 

(FT) of the new and repaired science instruments. In 

addition, ASD scientists Bruce Woodgate and Ted 

Gull—STIS PI and Deputy PI, respectively—contributed oversight to that instrument’s repair effort and 

were on shift during the STIS repair EVA, helping interpret the FT data. In October 2009, Dave Leckrone 

retired from the civil service and his post as Senior 

Project Scientist. George Sonneborn is serving as the 

Acting HST Senior Project Scientist until a replacement for Leckrone is found. Niedner currently serves 

as HST Observatory Project Scientist and Carpenter 

as its Operations Project Scientist.

After SM4 was completed, the telescope went through 

a ~4-month-long Servicing Mission Observatory Verification (SMOV) program, during which the new and 

repaired instruments were focused, aligned, characterized, and preliminarily calibrated, and the observatory as a whole was put through a battery of checkout and performance testing. Certainly the highlight 

of SMOV was the Early Release Observation (ERO) 

press conference on September 9, which proved both 

how spectacularly powerful the new WFC3 and COS 

are, and that STIS and ACS are back in operation after several years of being down. The only post-SM4 

downside to report is that in the eight months since 

SM4, the replacement Science Instrument Command 

& Data Handling (SI C&DH) unit has experienced 

three lock-ups in one of the internal Science Data 

Formatters (SDF). These are easily cleared by powercycling the entire SI C&DH, and there is no evidence 

that this is anything but a rare and subtle microcircuit 

timing hiccup, as opposed to degrading components. 

The telescope is scientifically non-operational only for 

about a day after each lock-up, and at the apparent 

modest rate of occurrence there is not a significant risk 

to HST productivity.

The “SM4 instruments”—WFC3, COS, STIS, and 

ACS—are working spectacularly. The remainder of 

in SM4, is at the time of this writing being prepared 

for a restart of its cryocooler. Because NICMOS only 

receives 1.4 percent of HST’s total observing time, 

failure to restart the instrument will not compromise 

the telescope’s output or long-term scientific legacy.

ASD’s role in Hubble is substantial, as its personnel 

continue to play a vital role in servicing, operating, 

and using Hubble. In 2009, five scientists from ASD 

served as full-time HST Project Scientists: Dave Leckrone (Senior Project Scientist), Mal Niedner (Deputy 

Senior Project Scientist), Randy Kimble (Development Project Scientist and WFC3 Instrument Scientist), Ken Carpenter (Operations Project Scientist), 

and Stephen Rinehart (Associate Project Scientist). 

WFC3 produced these four stunning images as 

part of the SM4 Early Release Observation (ERO) 

program. Clockwise from upper left: the “Butterfly,” 

a planetary nebula also known as NGC 6302; the 

“Stephan’s Quintet” compact group of galaxies; a 

portion of the Carina nebula showing a pillar of gas 

and dust in which stars are forming; and the heart 

of the globular cluster Omega Centauri, showing 

through their colors the broad range of stellar types 

present in the cluster.
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Astrophysics Science Division: Research and Missions

this report describes some early post-SM4 science with 

the new instruments, starting with WFC3, the facility instrument whose development was managed and 

largely carried out by GSFC.

WFC3. Although the WFC3 ERO images clearly 

showed the instrument’s power, two scientific observing programs in particular are quantifying that 

power. The instrument’s infrared channel (0.8–1.7m) 

is being used in a 2009–2010 repeat of the seminal 

2004 “Hubble Ultra Deep Field” (HUDF) carried out 

with ACS in the visible-red. At this point, although 

the 192-orbit program (G. Illingworth, PI) has not 

yet completed its data-taking, the results are spectacular. Due to the non-proprietary status of the new 

HUDF data, multiple research teams are writing papers on them, and while the teams’ results are different 

in the details, one thing all scientists agree on is that 

the Hubble Program has delivered a superb camera to 

HST that is substantially exceeding expectations. The 

speed with which WFC3/IR is picking up z ~7 galaxies exceeds that of the earlier NICMOS efforts by 

factors of 40 to 50 times, a performance metric that 

exceeds pre-flight calculations. The WFC3/IR HUDF 

has gone deeper than that, however, having crossed into 

the z = 8–9 range, with some indication of a few z ~ 10 

objects being detected as well. Translated into cosmic 

time, WFC3/IR is probing the zoo of early galaxies to 

within ~500 million years of the Big Bang. Data such 

as these clearly serve as a bridge to JWST.

The speed with which WFC3/IR is 

picking up z ~7 galaxies exceeds that of 

the earlier NICMOS efforts by factors 

of 40 to 50 times, a performance metric 

that exceeds pre-flight calculations. The 

WFC3/IR HUDF has gone deeper than 

that, however, having crossed into the 

z = 8–9 range.

The second program mentioned above is that designed 

by the WFC3 Science Oversight Committee (SOC), 

called “Early Release Science” (ERS). ERS utilizes 214 

orbits of non-proprietary Hubble time and exercises 

both the WFC3 IR and UVIS (200–1000 nm) channels to address two themes: star formation in nearby 

resolved galaxies, and star formation/galaxy assembly at half the Hubble time. As opposed to going 

ultra-deep in the near-IR along three boresights (the 

HUDF/IR), the second (distant) ERS theme tiles (in 

a 2 × 4 pattern) a portion of the large GOODS south 

field in UV and IR filters, which with pre-existing 

The deep WFC3/ERS Theme 2 (“Star Formation at half the Hubble Time”) field, a 2 × 4 tiled mosaic of ~ 40 

sq. arcmin of the GOODS-South field. Deeply panchromatic, the image contains 10 passbands of imaging, 

including several from ACS, extending from 225nm to 1600nm.
Astrophysics Science Division: Research and Missions

54

ACS visible-light images represents a panchromatic 

range of total spectral coverage. In spite of its somewhat shallower depth, ERS/Theme 2 is reaching redshifts of ~7–8, and use of the photometric drop-out 

technique in the UV is revealing star formation and 

other properties important to galaxy assembly at z = 

1–3, the redshift interval during which universal star 

formation and galaxy assembly processes were peaking. 

Theme 1 takes a massively multi-filter, panchromatic 

approach to address star formation in nearby, resolved 

galaxies such as the spiral M83. The early results from 

this theme are equally spectacular, showing among 

other things the power of WFC3’s very full and diverse set of filters, its exquisite angular resolution over 

a wide field, and its unmatched ability to “go deep” on 

objects with crowded point sources. The M83 images 

show hundreds of young super star clusters of various 

ages, and scores of supernova remnants. 

COS. While not a facility instrument like WFC3, the 

Cosmic Origins Spectrograph (James Green, PI, University of Colorado/Boulder) is an instrument that in 

the design, development, and testing phases benefited 

from extensive involvement of the ASD-staffed Hubble Project Science Office. 

Early results from the COS Instrument Development 

Team (IDT; Green et al.), as well as those from General Observers (GOs) whose programs are executing 

early, demonstrate that COS is more than living up to 

its promise. COS is a purely UV spectrograph (115-

320 nm) designed for high sensitivity, enabling many 

high-impact programs to execute relatively quickly, 

programs of the sort that, if possible at all with STIS 

(many were/are not), only executed with a much larger 

investment of observing time and with substantially 

lower signal-to-noise.

COS was designed and built with, among other 

things, detailed studies of the intergalactic medium, 

its relationship with galaxies and their growth, and the 

creation of heavy elements with cosmic time in mind. 

Early results are beginning to come in on all these 

themes as high-S/N absorption-line spectra along 

sightlines to distant quasars are probing in unprecedented detail the baryonic component of the “cosmic web.” Some of those sightlines pass close enough 

to imaged galaxies to probe the chemical content and 

physical state of their halo gas. And observations of 

Comparative spectra—from COS and the firstgeneration Goddard High Resolution Spectrograph 

(GHRS)—of the active galactic nucleus of 

Markarian 817. Powered by a central supermassive 

black hole, Mrk 817 expels large amounts of matter 

outward in time-variable winds. The upper COS 

spectrum, taken in less than nine percent of the time 

GHRS needed, shows that a hydrogen cloud seen in 

absorption in 1997 has disappeared by 2009.

COS observed a long sightline to a quasar at between 

7 and 8 billion years of look-back time in this ERO 

observation, detecting the absorption lines of many 

elements. Five times as many hydrogen lines were 

seen as with previous instruments, and in only one 

quarter the observing time. This is an indication of 

COS’s extreme ultraviolet sensitivity.
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Astrophysics Science Division: Research and Missions

supernova remnants are detecting the nucleosynthetic 

products of supernovae at levels of detail (high S/N at 

excellent spectral resolution) that were just not possible with STIS. Rounding out the early COS science 

results are programs characterizing exoplanetary atmospheric constituents and the time-variable kinematics 

of active galactic nuclei.

STIS and ACS. ASD was substantially involved in the 

repair efforts of STIS and ACS, and it is gratifying 

to see these two (still) immensely important instruments performing at the level we last knew (in 2004 

and 2007, respectively), the one exception being the 

unsuccessful attempt to restore the ACS High Resolution Channel (HRC). Return of HRC operability 

was, however, not the reason for the ACS repair effort. 

It was known from the beginning to have no better 

than a 50-percent probability of success, given that the 

target of the repair was the much more highly used 

(and important) Wide Field Channel (WFC). WFC 

was restored, and with a reduction of the WFC/CCD 

read noise from the ~5 to ~4 electron level, WFC is 

in some ways better than in January 2007. This was 

a remarkable accomplishment directly attributable to 

the use of an ASIC (“Application Specific Integrated 

Circuit”) in the replacement CCD control electronics. 

Although they are both electronically “single string,” 

STIS and ACS offer outstanding promise to the rejuvenated Hubble and are key components in the deep 

“tool kit” now available to astronomers.

With its new breadth of capabilities—many never before present on the telescope—Hubble is now more 

scientifically powerful than ever. With five, and hopefully as many as 10, years ahead of it, this observatory’s 

best epoch of discovery may well lie ahead.

Mal Niedner, for the Hubble Project Science Office, 

January 19, 2010. 

The Galaxy Evolution Explorer (GALEX)

The Galaxy Evolution Explorer (GALEX), a Small 

Explorer (SMEX) ultraviolet survey mission, is in its 

sixth year of science operations. All flight and ground 

systems are currently healthy, with the exception of 

the Far-UV detector; recovery efforts for the FUV are 

in progress. 

Most of the GALEX science operations are at Caltech. 

The core of the science team is also at Caltech, with 

smaller groups at Columbia, JHU, UCLA, Carnegie, 

and GSFC. Approximately one-third of GALEX observing time is dedicated to a robust Guest Investigator program, operated by GSFC (30 to 35 GI programs annually). Susan Neff (ASD) is the GALEX 

Mission Scientist. 

GALEX is delivering its sixth (annual) GALEX Data 

Release (GR6) to MAST (Multi-Mission Archive at 

Space Telescope), which serves both GRs and GI data 

to the scientific community. GALEX is primarily a 

survey instrument, designed to obtain large, homogeneous imaging samples in two bandpasses (Far-UV, 

1350–1800Å, and Near-UV, 1800–2800Å) that are 

sensitive tracers of recent star formation. The resulting 

samples are cross-matched with wide and deep surveys 

at other wavelengths; a particularly rich match is with 

the Sloan Digital Sky Survey. GALEX also can provide wide-field, low-resolution spectroscopy, useful, 

e.g., for identifying HST/COS targets or for variable 

objects in the Kepler field. Time-tag capabilities allow 

observers to determine a sampling time post facto, e.g., 

for identifying stellar pulsation modes. 

The primary GALEX mission (completed in late 

2007) had the goals: calibrate UV observables to star 

formation rate (SFR); measure star-formation history 

(0 < z < 1.5); and explore the UV universe. The GALEX Extended Mission (EM), endorsed by the 2006 

and 2008 Senior Reviews and up for review again in 

2010, is carrying out Legacy Surveys designed to: extend the UV/SFR calibration to low-mass, low-metallicity, transitional, or rare galaxies; relate star-formation history to other variables such as environment, 

mass, halo mass, assembly history, and star-formation 

regime; and determine the relative importance of the 

primary drivers of SF, such as galaxy assembly history, 

feedback from AGN, contributions from dust, or fractions of different gas phases. 

GALEX observations have been used to determine the 

cosmic star-formation (SF) history in the nearby universe, and to show that while SF occurred mostly in 

massive galaxies over the period 1 < z < 4, after that 

it moved to less and less massive hosts (Martin et al. 

2007; Schiminovich et al. 2005; Arnouts et al. 2010, 

in prep). 
Astrophysics Science Division: Research and Missions

56

The UV-optical color-magnitude diagram (UVOCMD) is a powerful tool for separating and relating 

galaxy types, properties, and evolutionary histories, 

largely because of the great leverage obtained with 

the UV (SFR)—optical/NIR (stellar mass) color. The 

UVOCMD can be measured accurately in very distant 

samples, and may be considered an Hertzsprung-Russell (HR) diagram for galaxies in which stellar mass 

is the major predictor of galaxy properties. GALEX 

UVOCMDs first identified the tendency of AGN to 

occur preferentially in the “green valley” and demonstrated that galaxies migrate both directions across the 

valley (Wyder et al., 2007; Schiminovich et al., 2007; 

Martin et al., 2007). More recent GALEX work has 

shown that low-mass galaxies in the green valley are 

mostly moving from blue to red (“quenching”), while 

higher mass galaxies are more evenly split between 

“quenching” and “bursting”; this is consistent with 

small galaxies losing their gas and massive galaxies undergoing microbursts of star formation as they accrete 

new material (Martin et al. 2010, in prep).

Heckman et al. (2005) discovered a rare population 

UV-luminous Lyman-Break Analogs (LBAs), which 

are the fastest-evolving component of the UV galaxy population. (Schiminovich et al., 2005). Their 

lack of dust (relative to other local starbursts, such as 

ULIRGs), suggests an early stage of chemical evolution (Basu-Zych et al. 2007; Hoopes et al. 2007). HST 

images show that they represent a complex merger of 

multiple, lower-mass, gas-rich subunits that echo the 

morphology and physical properties of high-z LBGs, 

Lyman Break Analogs, as seen by HST (red) and GALEX (blue), from Overzier et al. (2008) , showing that 

the LBAs often consist of multiple regions of intense star formation, indicative of merging activity.
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Astrophysics Science Division: Research and Missions

low-mass galaxies, the IMF may be top-light relative 

to assumptions about a universal mass function. 

High Energy Astrophysics Science Archival 

Research Center (HEASARC)

Since 1990, the HEASARC has been an essential element of NASA’s astrophysics missions. The 

HEASARC’s archive services allow scientists to identify, display, cross-correlate, download, and analyze data 

from a variety of past and current missions—including ASCA, BeppoSAX, Chandra, CGRO, Einstein, 

Fermi, INTEGRAL, ROSAT, RXTE, Suzaku, Swift, 

WMAP, and XMM-Newton—and provide access to a 

wide range of multiwavelength sky surveys, astronomical catalogs and other resources. The HEASARC’s scientific and technical staff produces a variety of widely 

used software packages, provides expertise in the analysis of archived data, and helps to evolve archive interfaces to better serve the science community. The data 

and software standards developed by the HEASARC 

provide the underlying infrastructure for the interpretation of data from a wide variety of missions, substantially reducing mission costs while increasing science 

return. 

The HEASARC archive is now in excess of 25 terabytes 

(TB), having grown by 7 TB in 2009, and contains 

data from eight active missions as well as about 30 

space-based missions and sub-orbital experiments that 

are no longer operational. Papers using HEASARC 

data comprise 10 percent of the total astronomical 

literature and include some of the most highly cited 

papers in the field. The HEASARC Office is led by Dr. 

Alan Smale, with Project Scientists Dr. Lorella Angelini (HEASARC) and Dr. Gary Hinshaw (LAMBDA).

In 2009, the HEASARC began a major effort to renovate its underlying archive software, led by Dr. Tom 

McGlynn. The new system will be faster, more portable, and more capable. Initial alpha releases of the 

software were made in Fall 2009 and the HEASARC 

plans to make the first versions available to the public in Spring 2010. All tables and metadata have been 

ported to a free PostgreSQL database and new web 

technologies are being used to serve HEASARC data. 

In addition, the HEASARC archive and web site are 

currently transitioning into a virtualized computer enbut seen in much more detail (Overzier et al. 2008; 

Basu-Zych et al. 2009). 

GALEX has opened several new lines of investigation 

in the low-density regime. GALEX observations of 

Extended UV (XUV) disks has shown that these are 

frequent, occurring in ~30 percent of late-type galaxies 

(Gil de Paz et al. 2007, Thilker et al., 2007, Zaritsky 

and Christlein, 2008). In these XUV disks, GALEX 

detects star formation occurring at gas densities lower 

than those previously suggested as a “threshold” level. 

Thilker et al. (2010) have found a new type of dwarf 

galaxy forming out of a possibly primordial cloud of 

HI. Recent work by Madore et al (2010, in prep) has 

found that the XUV disks also occur in early-type 

galaxies. Bigiel et al. (2010, in prep) and Wyder et 

al. (2009) have found that the outer low-density regions of spirals and low-surface brightness galaxies as 

a group fall below the extrapolation of the “standard” 

star-formation relationship to gas density. Meurer et 

al. (2009) and Lee et al. (2009) have used GALEX 

data to show that, in low-surface-brightness regions/

M83 shows an XUV disk (blue) and an HI extended 

disk (red), from Thilker et al. (2005). Star formation 

is occurring in regions where the gas density is 

below the previously suggested “threshold.” The 

star-forming regions in the extended disk may have 

an IMF that is relatively light on the most massive 

stars.
Astrophysics Science Division: Research and Missions

58

vironment that will allow more efficient use of computer resources. Other elements of the ASD are expected to follow the HEASARC along this path.

The HEASARC is a core partner in a joint NSF/NASA 

program to manage and operate the U.S. Virtual Astronomical Observatory. As part of this effort, McGlynn developed the first implementation of the new 

IVOA Table Access Protocol (TAP) to support both 

parameterized queries and generic SQL-like queries. 

TAP interfaces in astronomy archives will allow the 

HEASARC to send complex queries to remote sites, 

and conversely to allow other astronomical software to 

easily integrate HEASARC resources. The HEASARC 

has developed a database tracking the conformance of 

all registered VO services against VO standards and 

coordinates a world-wide effort to raise the quality of 

VO implementations.

The HEASARC archive is now in 

excess of 25 terabytes (TB), having 

grown by 7 TB in 2009, and contains 

data from eight active missions as well as 

about 30 space-based missions and suborbital experiments that are no longer 

operational. 

McGlynn also leads the development of the popular 

community resource, SkyView. In 2009, SkyView 

added all-sky surveys from the WMAP mission. 

While SkyView used data in the underlying HEALPix projection, it is the first site to treat HEALPix 

data as a straightforward two-dimensional projection 

rather than a complex linear pixelization. This makes 

WMAP data much more accessible to the community 

in general. Other new surveys include the Sloan DR7, 

GALEX GR4, and Mellinger medium-resolution optical surveys. Features for overlaying constellations were 

added to SkyView, and an image gallery established 

to allow users to save interesting images has been very 

popular. 

During 2009, HEASARC programmers under the direction of Dr. Bill Pence coordinated five online public 

releases of the HEASOFT data analysis software package. This package contains about 2.5 million lines of 

code contained in over 500 individual analysis tasks 

for data from 11 high-energy missions supported by 

the HEASARC, as well as general analysis of astronomical data from other missions. There are about 

1,000 registered individual or institutional users of 

the HEASOFT package, which is essential for deriving new scientific results from the HEASARC’s large 

data archive. Notable new features provided in 2009 

include major enhancements to the XSPEC multimission spectral fitting program, and support for a 

new, more efficient image-compression technique that 

can compress astronomical images up to a factor of 10 

without loss of scientific information.

Dr. Steve Drake worked on the creation and/or updating of 57 Browse tables in 2009, of which 40 were 

brand new, bringing the total number of tables in 

Browse to just over 600 by the end of the year. Of 

the newly created tables, 20 were Chandra source lists, 

and the others included a broad range of missions 

including XMM-Newton, ROSAT, WMAP, SDSS, 

GALEX, CGRO, and INTEGRAL. Drake has also 

worked on a variety of the HEASARC’s web pages, 

perhaps most importantly the HEASARC’s  RSS feed, 

which also populates the HEASARC’s Latest News 

page. This RSS feed combines feeds from a number 

of our projects ranging from XMM-Newton through 

WMAP, and also contains a number of wider interest 

items such as upcoming proposal and meeting deadlines. In 2009, three to four new items per week appeared in the HEASARC RSS/Latest News, providing 

an important and timely resource to the astronomical 

community.

A landmark event was the opening of the Fermi archive in August 2009. Dr. Mike Corcoran provided 

code to create transient and monitored-source lightcurves and create a web page displaying these lightcurves. The Fermi LAT Bright Source list was released 

by the Fermi project and implemented by Corcoran and programmer Ed Sabol as a searchable table 

within Browse. Corcoran and programmer Pan Chai 

worked with the Fermi project to implement the 

GBM response matrix generator in HERA, allowing users to access GBM spectra, and perform spectral analysis via the web without having to download 

and install any software. The Fermi calibration data 

for the GBM and LAT instruments were released by 

the Fermi project and implemented in the HEASARC 

calibration database (CalDB) by Corcoran. This in-
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Astrophysics Science Division: Research and Missions

including an NSTA webinar, and published an article 

about Cosmic Times in NSTA's The Science Teacher

journal for high-school teachers. 

The HEASARC continues to send out formal education materials to teachers and workshop providers; but 

in the past year, we branched out to supply our materials to the Night Sky Network, an organization run by 

the Astronomical Society of the Pacific consisting of 

more than 200 amateur astronomy clubs around the 

country. These clubs have used the Imagine the Universe CDs not only for their star parties and teacher 

workshops, but for other events and audiences such as 

the National Federation of the Blind, a city symphony, 

several senior citizen centers, a summer camp for children of incarcerated parents, a 4H group, the Science 

Olympiad training, and a dozen presentations at inner 

city libraries—all greatly expanding the audience for 

our materials. 

In 2009, Lochner successfully obtained funding 

through the Education & Public Outreach for Earth 

and Space Sciences (EPOESS) Program to continue 

the HEASARC’s production of the “Imagine the Universe!” DVD-ROM. The DVD-ROM captures the 

HEASARC’s education web sites, as well as the previous year’s Astronomy Picture of the Day pages. The 

grant will not only provide funding for production for 

three years, but also funding to determine more precisely the demographics of our audience and how they 

use the DVD-ROM.

Within the next four years, the HEASARC will ingest 

observations from eight currently operating missions 

and several upcoming missions, simultaneously serving data from these and more than 30 archival missions to the community from an archive that is projected to reach 40+ terabytes by 2012. Priorities within 

the 2010–2013 timeframe include the development 

and implementation of archival support for NuSTAR, 

Astro-H, and GEMS data under the direction of Dr. 

Lorella Angelini, and two ground-based CMB experiments ACT and SPT, under the direction of Dr. Gary 

Hinshaw; continuing support for the HEASARC’s 

exponentially growing data holdings and retrievals; a 

closer integration of archive access and analysis tools; 

development of science-based topical archives; and enhanced interoperability with other archive centers and 

the Virtual Observatory. 

cluded definition of the CalDB index files for both 

instruments, documentation regarding keyword usage, and construction of an update pipeline.  Corcoran also improved the remote retrieval software to 

provide more consistent usage for anyone using the 

remote data access facility to access calibration data. 

In 2009, there were a total of 44 updates of the Swift, 

Suzaku, Chandra, RXTE, and Fermi CalDB areas.

In 2009, Dr. Keith Arnaud participated in the releases of v6.6 and v6.7 of HEASOFT. This included 

a major new release of XSPEC (v12.5) that included 

many new models, support for algebraic models defined on-the-fly, improved estimation of uncertainties 

on fluxes, and a first step at parallelization for multicore processors. This release also included a new version of EXTRACTOR with region-filtering now using 

(fast) internal CFITSIO code. Arnaud has continued 

to develop XSPEC with current emphasis on designing methods to allow parameterized modeling of the 

response, more flexible plotting, and preliminary work 

on a Python interface. In collaboration with Dr. John 

Baker (GSFC) and colleagues, Arnaud has continued 

work on using XSPEC for simulations of gravitational 

wave data analysis. This work included responding 

to the Mock LISA Data Challenge as well as writing 

the core of a new software system to tie together the 

different projects underway. Arnaud was a successful 

co-I with Goddard and UMD colleagues on a NASA 

theory proposal to assess the importance of recent numerical relativity results on the LISA data analysis.

Under the direction of Dr. James Lochner, the 

HEASARC E/PO program continues to fulfill its mission of bringing high-energy astrophysics and cosmology to teachers and students. In 2009, the Cosmic 

Times project was completed. This set of six posters 

and lesson plans describes how our knowledge of the 

universe has changed over the past hundred years. 

Each poster mimics the front page of a newspaper 

with articles about key discoveries in this history. The 

posters were printed mid-year and by end of the year 

more than 1,000 sets had already been distributed. The 

Cosmic Times web site provides resources for teachers, 

including the lessons and a teacher guide, and in 2009 

was revised to include online versions of the posters. 

A third version of the poster articles was developed 

to make them more accessible to students in grades 

7–9. We conducted five workshops on Cosmic Times, 
Astrophysics Science Division: Research and Missions

60

system. Time on the telescope will be allocated to the 

community through annual peer-reviewed proposals, 

in a manner similar to Hubble. The prime contractor 

is Northrop Grumman; the Science and Operations 

Center is located at the Space Telescope Science Institute. JWST is a partnership between NASA and the 

European and Canadian Space Agencies.

The ASD provides scientific direction for JWST 

through eight project scientists. The Senior Project 

Scientist is John Mather and his deputy is Jonathan 

Gardner. The other members of the team: Matthew 

Greenhouse (Instrumentation), Bernard Rauscher 

(deputy); Mark Clampin (Observatory), Charles Bowers (deputy); Randy Kimble (Integration and Test) 

and George Sonneborn (Operations). The ASD is currently seeking to hire a Deputy Project Scientist for 

Operations.

Mather chairs the JWST Science Working Group 

(SWG), and the Project Scientists are thoroughly integrated with the management and engineering teams, 

participating in reviews, project meetings, serving 

on change-configuration boards, and participating 

in decisions. The JWST SWG published a thorough 

description of the JWST science goals and technical implementation as a special issue of the refereed 

journal, Space Science Reviews (Gardner et al. 2006). 

It has since also updated and extended the science 

case in a series of white papers that include astrobiolWilkinson Microwave Anisotropy Probe 

(WMAP)

As of January 2010, WMAP had been in orbit for 

8.5 years and is still taking data at the Sun-Earth second Lagrange point (SEL-2). Aside from a few minor 

hardware problems over the life of the mission, there 

has been no significant degradation anywhere on the 

observatory. The current plan is to continue operating 

the mission until the end of fiscal year 2010, and then 

spend several years performing the final data analysis 

and archiving.

The scientific results from the first seven years of operations were recently published, and included the following highlights:

• Reported the first direct detection of pre-stellar 

helium, providing an important test of the Big 

Bang prediction.

• Placed 50% tighter limits on the standard model 

of cosmology (Cold Dark Matter and a Cosmological Constant in a flat universe), with no compelling sign of deviations from this model.

• Placed strong constraints on dark energy and the 

geometry of the universe.

• Placed new constraints on the number of neutrino-like species in the early universe.

• Detected, with very high significance, temperature shifts induced by hot gas in galaxy clusters.

• Produced a visual demonstration that the polarization pattern around hot and cold spots follows 

the pattern expected in the standard model of cosmology.

Further details on WMAP and its discoveries can be 

found at the WMAP website map.gsfc.nasa.gov.

Projects in Development 

James Webb Space Telescope

The James Webb Space Telescope (JWST) is a large 

(6.5m), cold (50K), facility-class, general-purpose 

observatory that will be launched into orbit around 

the Sun-Earth L2 point in 2014. It is the successor 

to the Hubble and Spitzer space telescopes. Its science 

goals range from detecting the first galaxies to form 

in the early universe to observing objects in our solar 

In early 2010, James Webb Space Telescope 

mirror segments were prepped to move into the 

X-ray and Cryogenic Facility, or XRCF, at NASA’s 

Marshall Space Flight Center in Huntsville, Ala. 

NASA/MSFC/Emmett Givens
61

Astrophysics Science Division: Research and Missions

and are ready for the measurement of their cryogenic 

figure at Marshall Space Flight Center (MSFC), in 

preparation for the final stage, known as cryo-polishing. An engineering-demonstration segment has completed cryo-polishing and will be verified in a cryogenic vacuum test in January 2010. Following this final 

test, the segment will be ready for gold coating.

Development of the ground system at Space Telescope 

Science Institute is progressing. They recently formed 

the JWST Space Telescope Advisory Committee to 

give advice on the readiness for science operations, and 

to represent the General Observer community.

The ASD is directly responsible for two hardware 

items, both within the Near-Infrared Spectrograph 

(NIRSpec), an instrument that is part of the ESA contribution to the mission. The Microshutter Assembly 

(MSA) is led by PI Harvey Moseley with contributions from Robert Silverberg and a number of contractor scientists. The MSA will enable simultaneous 

spectra of more than 100 objects—the first time that a 

true multi-object spectrograph has flown in space. The 

flight MSA is currently in test and will be delivered to 

ESA early in 2010. The detectors in the NIRSpec are 

also being built at Goddard, under the leadership of 

Bernard Rauscher, and will also be delivered in 2010. 

Both Rauscher and Moseley are members of the NIRSpec Science Teams and will participate in their Guaranteed Time Observations.

Astro-H

The X-Ray Astrophysics Laboratory is collaborating 

with ISAS/JAXA to implement an X-ray calorimeter 

spectrometer for the Astro-H mission. In response 

to the 2007 NASA Announcement of Opportunity 

soliciting investigations for Small Explorer (SMEX) 

missions and Missions of Opportunity (MO), a group 

headed by Richard Kelley of the X-Ray Astrophysics 

Laboratory was selected to provide key components of 

a high-resolution X-ray calorimeter spectrometer that 

will constitute one of the observatory’s primary science 

instruments. Among Code 660 scientists, Caroline 

Kilbourne and Scott Porter are responsible for the detector subsystem and Peter Serlimitsos and his team of 

Takashi Okajima and Yang Soong are responsible for 

the X-ray mirror.

ogy, exoplanet coronagraphy, exoplanet transits, firstlight galaxies, resolved stellar population, and solar 

system observations. The white paper on exoplanet 

transits is being revised and prepared for refereed 

publication. The Space Science Reviews paper and the 

white papers are available from jwst.gsfc.nasa.gov/

scientists.html.

The JWST Project is now in phase C/D, and the project is working towards the Critical Design Review 

(CDR) in mid-2010. All four instruments have passed 

their CDRs. Engineering units of the instruments will 

arrive at Goddard in 2010, and the flight instruments 

will arrive in 2011. Most of the instrument flight 

hardware and all of the flight detectors are selected and 

are in the process of integration. The Integrated Science Instrument Module (ISIM) flight structure was 

delivered to Goddard in 2009, and development of 

ISIM-level test facilities is underway. The GSFC Space 

Environment Simulator (SES) cryogenic vacuum 

chamber was modified by the JWST project with a 

liquid helium shroud, the largest such shroud in the 

world. The project is currently integrating the cryogenic telescope simulator that will be used in the SES 

chamber to test the ISIM. 

The 18 primary mirror segments, three spare segments, 

and the secondary, tertiary, and fine steering mirrors 

have been constructed out of lightweight beryllium. 

Most of the segments have completed fine polishing 

NASA engineers check out the unwrapped ISIM 

structure in the Goddard clean room. The ISIM 

Structure supports and holds four Webb telescope 

science instruments. NASA/Chris Gunn
Astrophysics Science Division: Research and Missions

62

• Determine the spin of black holes and the equation of state of neutron stars; 

• Trace shock-acceleration structures in clusters of 

galaxies and SNRs; 

• And investigate the detailed physics of jets. 

Achieving these objectives requires the SXS and three 

additional scientific instruments to provide a very 

broad, simultaneous energy bandpass. The Hard 

X-ray Imager (HXI) will perform sensitive imaging 

spectroscopy in the 5–80 keV band; the non-imaging 

Soft Gamma-ray Detector (SGD) extends the AstroH energy band to 300 keV, and the Soft X-ray Imager 

(SXI) expands the field of view with a new-generation 

CCD camera.

The proposed SXS science investigation comprises 

building and delivering the SXS instrumentation and 

carrying out a six-month observing program in collaboration with ISAS/JAXA. The baseline mission includes two years of funding for the SXS science team 

and support for processing and archiving the SXS 

data for a total of three years. A Science Enhancement 

Option (SEO) was also proposed to provide the U.S. 

community with access to Astro-H beyond the baseline program. Under the SEO, U.S. scientists will be 

able to propose for Astro-H observing time and obtain 

grant support. Working collaboratively with JAXA, a 

U.S. Guest Observer Facility will process, distribute, 

and archive data from all four Astro-H instruments, 

and provide observers with analysis tools and support.

This year saw two major accomplishments for the 

SXS. In June 2009, the project was successfully elevated to Phase B, the design phase, following an extensive review at NASA Headquarters (“Key Decision 

Point-B”). In November 2009, a revised plan for the 

SEO, including budget profile, was favorably received 

by NASA Headquarters.

Gravity and Extreme Magnetism SMEX 

(GEMS) 

The information contained in the polarization of 

X-ray fluxes has long been viewed as the unexplored 

handle on the geometrical and magnetic structures 

of X-ray-emitting regions. Sensitivity to the effects of 

strong gravity around black holes and the virtual pair 

creation of strong magnetic fields in neutron stars give 

The Soft X-Ray Spectrometer (SXS) will consist of a 

36-pixel X-ray calorimeter array with better than 7 eV 

resolution (and a goal of 4 eV) to provide high-resolution X-ray spectroscopy over the 0.3–12 keV band 

with moderate imaging capability. The Goddard team 

is to provide the detector system, adiabatic demagnetization refrigerator (50 mK operational temperature), 

electronics, blocking filters, and X-ray mirror, while 

ISAS/JAXA is responsible for the dewar system and 

the rest of the science instruments, the spacecraft, 

launcher, and mission operations. The dewar will be 

a hybrid cryogen/mechanical cooler system for redundancy, and the X-ray mirror will build on the Goddard legacy of providing lightweight, high-throughput 

mirrors.

Astro-H is a facility-class mission to be launched on a 

JAXA H-IIA into low Earth orbit in 2014. The AstroH mission objectives: 

• Trace the growth history of the largest structures 

in the universe; 

• Provide insights into the behavior of material in 

extreme gravitational fields; 
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Astrophysics Science Division: Research and Missions

polarization a special place as a probe of fundamental 

physics. 

In April 2009, the team for the Gravity and Extreme 

Magnetism SMEX (GEMS) held the site visit for the 

proposed SMEX mission for X-ray polarization measurements for a variety of black hole and neutron star 

X-ray sources. The review was held at the Orbital Sciences Corporation in Dulles, Virginia. At the end of 

June, we were delighted to learn that GEMS is one of 

the two selected SMEX missions from the 2007 SMEX 

AO and that GEMS will be the second of these to fly, 

after the solar mission IRIS from Lockheed Martin. 

The GEMS launch date is April 2014. In keeping with 

this date, the project has begun with a slow ramp-up. 

GEMS was proposed from the X-Ray Astrophysics 

Laboratory. Jean Swank is the Principle Investigator 

(PI), with Keith Jahoda Deputy PI. Timothy Kallman 

is the Chair of the Science Working Group. 

GEMS combines the X-Ray 

Astrophysics Laboratory’s interests 

in instruments and in the physics of 

astrophysical sources.

GEMS carries three telescopes, with each of the mirrors being a copy of the 4.5m-focal-length Suzaku 

mirror. The detectors behind the mirrors are Time 

Projection Chambers in which micropattern gas detectors record the tracks of photoelectrons as they lose 

energy. The mirrors and the polarimeters for GEMS 

are optimized for 2–10 keV. The spacecraft will rotate 

at 0.1 rpm to allow systematic affects to be detected 

and corrected. The rotation allows a student experiment from co-investigators at University of Iowa to 

measure the polarization at 0.5 keV by scattering these 

X-rays out of the beam from one of the mirrors into a 

small proportional counter. 

The 1972 rocket flight detection of polarization of 

the Crab Nebula X-ray flux was followed by spacecraft efforts to detect polarization in bright sources 

using Bragg scattering instruments. These had good 

sensitivity to the polarization of an X-ray but very low 

sensitivities as instruments. The sensitivity of the photoelectric effect to the polarization of the X-ray raised 

the possibility of more efficient instruments. To use 

this effect, it is necessary to track the ejected electrons 

whose distribution is peaked around the direction of 

the electric vector. In several early laboratory efforts to 

do this, the tracks were too short. It was achieved in 

a potentially practical way by Bellazzini at INFN, as 

reported in the paper by Costa et al. (2001). 

The GEMS polarimeters use the same physical effect 

with a more efficient geometry and will make possible 

measurement of polarization to an accuracy of about 

1% for representatives of stellar black holes, supermassive black holes, neutron star pulsars (including magnetars), and supernova remnants. The baseline science 

program can be carried out in nine months with 35 

targets. In the balance of a two-year mission, a General 

Observer (GO) program could measure the polarizations of as many more targets. The Science Operations 

would be set up to support GOs as well as the baseline 

mission.

GEMS combines the X-Ray Astrophysics Laboratory’s 

interests in instruments and in the physics of astrophysical sources. Polarization data, as well as timing 

and spectroscopy data, will provide a robust guide to 

resolving alternative interpretations of X-ray emission 

in various cosmic sources. 

Laboratory Development of X-ray Polarimetry. The 

charge signal associated with the photoelectric absorption of X-rays has been exploited over many years for 

imaging, timing, and spectroscopy. It has long been 

recognized that a polarization signature is also present, 

as the photoelectron direction is correlated with the 

photon electric-field vector. 

Work on micropattern gas detectors in ASD led to a 

2003 SMEX proposal for the Advanced X-Ray Polarimeter (AXP), in collaboration with Palo Alto Research 

Center and the Italian INFN and IASF-CNR. While 

AXP was not selected, funding for detector development permitted continued laboratory work. The polarimeters proposed for GEMS are several times more 

efficient than the AXP polarimeters. This increase in 

sensitivity was enabled by adopting a Time Projection 

Chamber readout geometry. The TPC is widely used 

in particle physics. In 2009, most laboratory efforts 

supported developing the TPC readout specifically for 

GEMS.
Astrophysics Science Division: Research and Missions

64

ASP uses a cryogenic Michelson interferometer to 

measure the differential spectrum between two independent inputs in two orthogonal linear polarizations. 

ASP will measure the frequency spectrum of the Stokes 

I, Q, and U parameters from 1 cm through 60 mm 

wavelength. Its high sensitivity and broad spectral coverage enable a range of science goals. The polarization 

on large angular scales encodes the ionization fraction 

as a function of redshift, providing critical inputs for 

models of reionization and structure formation. 

Measurements of the CMB blackbody spectrum provide an independent determination of reionization 

through the Sunyaev-Zeldovich spectral distortion 

and will search for evidence of dark matter decay or 

annihilation in the very early universe (107 < z < 103). 

ASP will measure the spectra of the temperature and 

polarization anisotropy to confirm their cosmological 

origin, and will measure both the far-infrared background and its power spectrum to test models of 

structure formation. Its measurements of the diffuse 

interstellar medium include full-sky maps of the major C+, N+, OI, and CO lines as well as thermal dust, 

free-free, and synchrotron emission.

International X-ray Observatory (IXO)

IXO is an international flagship X-ray observatory 

with joint participation from NASA, the European 

Space Agency (ESA), and Japan’s Aerospace Exploration Agency (JAXA). The mission was created in 2007 

by the merger of NASA’s Constellation-X and ESA’s 

XEUS. IXO is a facility-class mission for launch circa 

Measuring the direction of the photoelectron track in 

a practical detector is complicated by the fact that the 

photoelectron track length is small (< 10-2) compared 

to the photon absorption depth. However, Costa et al. 

(2001) demonstrated that a gas proportional counter 

with a finely pixelated readout can make polarization 

measurements in the X-ray band. Careful choices of 

gas composition and pressure allow tuning of the photoelectric path length; current practical technologies 

require that the photoelectron track be between 100 

and 1000 microns in the band of interest.

Over the last few years, members of the X-ray Astrophysics laboratory (Jahoda, Black, Hill, Deines-Jones, 

Swank) have concentrated on exploiting photoelectric 

polarimetry in geometries suitable for Explorer class 

missions. Recent efforts have centered on developing 

the Time Projection Chamber Readout as proposed 

for GEMS (Black et al. 2007). In this geometry, the 

track is drifted perpendicular to the photon direction 

of incidence to a readout plane. This innovation largely decouples detector depth (i.e., efficiency) from the 

ability to image the track (polarization sensitivity).

During 2009, we successfully demonstrated a TPC 

polarimeter that uses the ASIC-based readout required 

for GEMS, and demonstrated the efficiency of using 

rotation to remove instrumental signatures associated 

with the asymmetry of the TPC readout.

Mission Concepts

Absolute Spectrum Polarimeter (ASP)

The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission concept to measure the polarization pattern and frequency spectrum of the cosmic 

microwave background. ASP will measure the linear 

polarization produced by gravity waves excited during an inflationary epoch shortly after the Big Bang. 

Such a signal is expected to exist; its detection would 

have profound consequences for both cosmology and 

particle physics. Not only would it establish inflation 

as a physical reality, but it would provide a model-independent determination of the relevant energy scale 

(~1015 GeV) some 12 orders of magnitude beyond 

those accessible to particle accelerators.
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Astrophysics Science Division: Research and Missions

2021 that will address the leading astrophysical questions in the “hot universe” by providing breakthrough 

capabilities in X-ray spectroscopy, imaging, timing, 

and polarimetry.

IXO will measure the spin of black holes, a fundamental property that, for supermassive black holes, reveals 

whether black holes grow mainly by accretion or by 

mergers. IXO will reveal the physics of accretion near 

the last stable orbit, measuring general-relativistic effects in the strong field limit. For neutron stars, IXO 

will determine the mass-radius relationship, thereby 

constraining the equation of state and QCD models 

of matter at these densities. In galaxy clusters, IXO 

will measure the velocity structure, mass, and metallicity distribution of the dominant baryon component, 

the hot intracluster gas. Not only will this provide a 

deep understanding of evolution of large-scale structure, but samples of clusters at various redshifts provide important and independent constraints on the 

cosmological model and dark energy. 

Extending away from clusters and groups is the cosmic 

web, where half of the baryons in the local universe are 

expected to reside but have not been detected. IXO 

will detect these missing baryons and it can test predictions for the formation and topology of the cosmic web. Furthermore, IXO will yield insight into 

feedback mechanisms in the universe on many scales 

through studies of supernova remnants, outflows in 

starburst galaxies, and AGNs across cosmic time. 

Much of this science requires a panchromatic approach. IXO covers the 0.1–40 keV energy range, 

complementing the capabilities of the next-generation observatories such as ALMA, LSST, Webb, and 

30m ground-based telescopes. IXO builds on three 

decades of successful X-ray mirror development, including the currently operating Chandra X-ray Observatory (NASA) and XMM-Newton mission (ESA). 

The spacecraft configuration for IXO features a single, 

large X-ray mirror assembly and an extendible optical 

bench, with a focal length of 20m, and a suite of focal 

plane instruments. Areas of technology development 

include X-ray optics, detector and cooling systems. 

The NASA portion of this project is led by GSFC. 

The Project Scientist is Nicholas White, Deputy Project Scientist is Ann Hornschemeier, and the Observatory Project Scientist is Rob Petre. Project science support is provided by Steve Snowden, Tim Kallman, Tod 

Strohmayer, and Rita Sambruna. Will Zhang leads the 

mirror technology development; Richard Kelley, Caroline Kilbourne, and Scott Porter lead the calorimeter 

development.

Over the past year substantial effort has been devoted to providing input to the NAS Decadal Survey 

of Astronomy and Astrophysics. In early 2009, approximately 25 science white papers were submitted 

by scientists around the world, on topics that IXO is 

ideally suited to address. The mission team submitted 

a response to a request for information by the Decadal 

panel in April 2009, provided a written response to 

two sets of questions by the panel (June and July 

2009), and made an invited presentation to the Electromagnetic Observations from Space Panel during 

the June 2009 AAS meeting. Project team efforts are 

currently focused on providing input to ESA’s Cosmic 

Visions process.

Joint Dark Energy Mission (JDEM)

The 1998 discovery that the expansion of space is accelerating was described in the journal Science as the 

breakthrough of the year and one of the most important scientific problems of our time. The implication 

that three-quarters of the energy in the universe is due 

to an unknown entity called dark energy may one day 

revolutionize our understanding of cosmology and 

physics. Observations with ground-based and spacebased assets such as HST and WMAP confirmed the 

acceleration. However, a new space-based experiment 

is required in order to extend these measurements of 

dark energy to the early universe with high precision. 

Prior to 2008, NASA and its partner, the U.S. Department of Energy (DOE), solicited concepts for a 

dark energy mission. Three concepts were submitted: 

DESTINY, ADEPT, and SNAP. ASD scientists were 

involved in each of the three funded mission concepts. 

Benford, Carpenter, and Sonneborn were on the DESTINY (supernovae and weak lensing) science team; 

Moseley, Hinshaw, Oegerle, and Bowers were on the 

ADEPT (baryon acoustic oscillations and supernovae) team; and Woodgate, Rauscher, Kimball, and 

Greenhouse were members of the SNAP (supernovae 

and weak lensing) team. At that time the mission was 
Astrophysics Science Division: Research and Missions

66

(ISWG) to find a lower cost, yet scientifically worthwhile, “probe” concept. The scientists from ASD have 

been concentrating on the development of design 

specifications for each technique and optimal observing strategies.

Several studies are underway to reduce uncertainty 

and risk during the concept phase. A telescope study 

is being executed to develop detailed cost estimates 

and models for telescopes with primary mirrors having diameters in the 1.0- to 1.5-meter range. The telescope contractors are working closely with our team to 

ensure the cost estimates are reasonable and acceptable 

and the implementation straightforward. An Engineering Demonstration Unit (EDU) focal plane will 

be built in order to characterize the building, testing 

and use of HgTeCd detectors for dark energy studies. 

Our team is also working with Ames Research Center 

to test detectors for susceptibility to the effect of spacebased radiation.

The GSFC JDEM Project utilizes the skills of a broad 

cross-section of GSFC personnel for project management, science, resource management, and engineering. It is a collaborative effort across multiple GSFC 

directorates, including the Science, Engineering, and 

Flight Projects Directorates.

conceived to be PI-led. Programmatic changes were 

later made such that GSFC would be the lead NASA 

center for managing the project, working in collaboration with a DOE team at Lawrence Berkeley National 

Laboratory (LBNL). Science teams will be selected to 

participate in the mission at a later time.

The JDEM Project team at GSFC and the JDEM 

Project Scientist, Dr. Neil Gehrels, worked closely 

with a NASA and DOE selected Science Coordination Group (including ASD scientists Benford and 

Moseley) to develop a mission concept that was scientifically compelling and affordable. Many of the ASD 

scientists who supported the original three concepts 

now work as part of the JDEM team. In particular, 

K. Carpenter/667, G. Hinshaw/665, J. Kruk/JHU, 

Bernie Rauscher/665, and E. Wollack/665 are working as Deputy Project Scientists/Science Advisors to 

the GSFC management team. The team responded to 

the Astro2010 Decadal Survey RFI with concepts that 

utilized all three dark energy techniques. Recently, the 

team has been working closely with the DOE partners and the JDEM Interim Science Working Group 

An illustration of how the universe’s expansion rate 

is increasing in the current epoch. Astrophysicists 

have no understanding of what causes this 

acceleration. JDEM is designed to make the 

necessary measurements for a breakthrough in 

our knowledge of the “dark energy” that drives the 

acceleration.

Artist’s view of one of the concepts (IDECS) for a 

JDEM observatory.
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Astrophysics Science Division: Research and Missions

The Fourier-Kelvin Stellar Interferometer 

(FKSI) 

The long-term focus of planet-finding efforts at NASA 

has been directed toward the search for extrasolar terrestrial planets, like those in our own solar system, 

within the habitable zone around stars similar to our 

own Sun, e.g., F, G, and K main sequence stars. Our 

present theoretical understanding is that all stellar systems, including those with planets, form out of material in primordial disks. Thus, the formation of planets 

is intimately linked to the evolution of circumstellar 

disks, which for mature stars like our own Sun, have 

optically thin “debris disks” in their habitable zones.

Recent studies of the requirements for planet-findingand-characterization missions such as the Terrestrial 

Planet Finder (TPF) have shown that the amount of 

exozodiacal emission from warm and hot dust in the 

habitable zone is a crucial parameter. Observations 

of planets in stellar systems with more than about 10 

times the zodiacal light as our solar system will be extremely difficult, as exozodiacal dust emission (and/

or scattering) interferes with the observer’s ability to 

detect the faint emission from an earthlike planet. 

Thus it is crucial to observe all of the likely targets for 

TPF to determine the amount of exozodiacal emission around nearby stars with sufficient accuracy for 

the flagship missions. In particular, we must answer 

the question: What is the star-to-star statistical distribution of exozodiacal material in the habitable zone 

around nearby stars? The need for this measurement is 

documented in the report from the ExoPlanetary Task 

Force (Lunine et al., 2008). This measurement can be 

made with a small, spaceborne infrared interferometer 

having apertures ~0.5–1m in diameter and passively 

cooled to about 60 K.

One such implementation is the Fourier-Kelvin Stellar 

Interferometer (FKSI) mission, which is an infrared 

space interferometer composed of two 0.5m-aperture 

telescopes on a 12.5m baseline on a boom, operating 

in the spectral range 3 to 8 (or 10) microns, and passively cooled to about 60 K. Dr. William C. Danchi, 

senior scientist in the Laboratory for Exoplanets and 

Stellar Astrophysics, is the Principal Investigator for 

FKSI. The main goals for this mission are the measurement and characterization of the exozodiacal emission 

around nearby stars, debris disks, spectroscopic characterization of the atmospheres of known exoplanets, 

and the search for and characterization of super-Earths 

around nearby stars. 

Last year, with efforts funded by a Goddard Internal 

Research and Development (IRAD) grant, the FKSI 

team investigated if an enhanced version of FKSI that 

could detect and characterize many super-Earths and 

a few Earth twins was feasible within the expected cost 

cap for a mid-sized strategic or “Probe” mission. The 

enhanced version of FKSI consists of two 1-m telescopes separated by a 20-m baseline, passively cooled 

to 40K, with a science wavelength band from 5 to 

15 microns, and a Field-of-Regard of +/- 45 degrees 

from the ecliptic. Studies of the performance of the 

enhanced FKSI, using the TPF-I performance simulaComparison between the discovery space for exoplanets with FKSI and other mission concepts and 

techniques.

Engineering model of the enhanced FKSI design, 

called FKSI-2.
Astrophysics Science Division: Research and Missions

68

tor of Dubovitsky and Lay (2004), demonstrated that 

with these parameters, the enhanced FKSI, or FKSI-2, 

can detect and characterize one-Earth-radius planets 

around four nearby G and K stars, and detect 34 twoEarth-radius super-Earths and characterize 16 of them, 

in the habitable zones of these stars. An engineering 

realization of FKSI-2 is displayed below, as well as a 

chart that shows the unique discovery space available 

to this mission concept. Note that FKSI-2 is the only 

proposed mission concept in a Probe-class budget category that can detect and characterize Earth-twins and 

super-Earths in the habitable zone of nearby stars (see 

Danchi et al. 2009 for more information on FKSI-2).

The FKSI mission has been reviewed in the context of 

the Exoplanet Community Forum 2008 and has been 

included in the notional timeline developed for the 

area of “Direct Infrared Imaging of Exoplanets” as a 

candidate for a mid-sized or Probe-class strategic mission (see the Exoplanet Community Forum Report, 

Chapter 4). FKSI has also received international recognition and collaborators in Europe have been able 

to include FKSI as a “mission of opportunity” in the 

plans for the French space agency (CNES) and the 

European Space Agency (ESA). Most of the technical risks have been retired through technology investments for JWST, SIM, and TPF-I/Darwin, and most 

technologies are at a Technical Readiness Level (TRL) 

sufficient for advancement to Phase A. This mission 

could receive a Phase-A start in the next 2–5 years 

with only modest technology investments.

Stellar Imager (SI)

The Stellar Imager (SI) Vision Mission (see 

hires.gsfc.nasa.gov/~si) is a UV-optical aperturesynthesis spectral imager with some 30 apertures, each 

at least one meter in diameter, and spread over baselines 

up to a kilometer across. A central beam-combing 

hub with focal-plane instrumentation provides an 

angular resolution of 0.1 milliarcsecond, or more than 

200 times that of Hubble Space Telescope (HST). It will 

provide heretofore unattainable views of the surfaces 

and (via spatially-resolved asteroseismology) interiors 

of other solar-type stars, of the inner regions and 

winds of Active Galactic Nuclei (AGN), and of the 

dynamics of many systems and processes throughout 

the universe.

SI is a Flagship “Landmark Discovery” Mission in the 

2005 Heliophysics Roadmap and a potential implementation of the UV/Optical Interferometer (UVOI) 

in the 2006 Science Program for NASA’s Astronomy 

& Physics Division.

The primary goal of this cross-theme mission is to 

revolutionize our understanding of:

• Solar and Stellar Magnetic Activity and their impact on space weather, planetary climates, and life

• Magnetic and accretion processes and their roles 

in the origin and evolution of structure and in the 

transport of matter throughout the universe

• The close-in structure of AGN and their winds 

• Extrasolar planet transits and disks

The PI of the Stellar Imager concept development is 

Dr. Kenneth Carpenter (GSFC/667). He leads a large 

collaborative team of about a dozen GSFC personnel 

plus co-investigators at some 18 external institutions 

(academic, aerospace, and international) established 

for the Vision Mission Study and expanded, at low 

level of effort, in the following years. GSFC’s role is 

to continue to foster and coordinate the further development of the science program goals, and a mission 

architecture to satisfy those goals—and to pursue and 

An array of thirty 1-m mirrors flies in precision 

formation to form a virtual parabola 500-m across. 

This structure would enable submilliarcsecond 

spectral imaging of many astronomical objects. 

Shown in the inset above is a solar-type star imaged 

in the light of CIV emission lines.
69

Astrophysics Science Division: Research and Missions

encourage the development of the technologies needed to enable the mission in the 2020s.

The primary activity of the SI Team (lead by K. Carpenter and R. Lyon/GSFC-667, K. Schrijver/LMATC, 

M. Karovska/CfA, D. Mozurkewich/Seabrook Engineering, and S. Kraemer/CUA) in 2009 has been to 

prepare and submit input to the 2010 Astrophysics 

Decadal Survey on the science goals of SI, its technology development needs, and a mission architecture 

that would achieve the science goals. The Team has 

also continued to describe to various committees and 

the astronomical community the value of the SI observatory for addressing both NASA Astrophysics and 

Heliophysics Division science goals and the ways in 

which the mission could potentially be enhanced by 

use of the Constellation Architecture to launch and/

or service it.

The whitepapers submitted to the Astrophysics 

Decadal Survey include: “Mass Transport Processes 

and their Roles in the Formation, Structure, and Evolution of Stars and Stellar Systems” (Carpenter, K. G. 

et al. 2009); “Dynamos and Magnetic Fields of the 

Sun and other Cool Stars, and their Role in the Formation and Evolution of Stars and the Habitability of 

Planets” (Schrijver, C. J. et al. 2009); “Active Galactic 

Nuclei and their Role in Galaxy Formation and Evolution” (Kraemer, S. et al. 2009); “Technology Development for Future Sparse Aperture Telescopes and Interferometers in Space” (Carpenter, K.G., et al. 2009); 

“Stellar Imager (SI) – A UV/Optical Interferometer 

(UVOI) Viewing the Universe in High Definition” 

(Carpenter, K. G., et al. 2009).

Extrasolar Planetary Imaging Coronagraph 

(EPIC)

Direct imaging/characterization of extrasolar planets 

is predicated on the ability to unambiguously detect 

planets in the presence of diffracted/scattered light 

from the parent star, its exozodiacal light, and other 

objects in the field of view. Astrometric missions can 

detect Earth-mass planets and determine orbital parameters yet cannot determine the zodiacal light—

crucial for a future exosolar terrestrial imaging mission. 

EPIC is an alternative approach which images and 

characterizes jovian planets and exozodi disks around 

single, binary and ternary stars. It would provide the 

first direct measurements of a range of fundamental 

physical characteristics of exosolar giant planets—a 

step toward the long-term goal of imaging exosolar 

terrestrial planets (Mark Clampin, PI; Gary Melnick/

CfA, Deputy PI; Rick Lyon, Project Scientist).

Science goals are achieved by a 1.65-meter telescope 

coupled to a visible nulling coronagraph (VNC) delivering broadband starlight suppression (109

 @ 125 

mas) and permitting direct observation and broadband (0.4–1.0 mm) spectral characterization. EPIC 

is aligned with the strategic objectives of NASA per 

Artist’s concept of the EPIC spacecraft. 

NASA/EPIC
Astrophysics Science Division: Research and Missions

70

“The New Age of Exploration” and fulfills the goal of 

“Vision for Space Exploration,” which calls for planet 

searches. EPIC meets the recommendations of the 

Exoplanetary Task Force (ExoPTF) to characterize 

exosolar disks and is a funded Astrophysics Strategic 

Mission Concept study (ASMC). The results of the 

study will be presented to the Decadal review. 

EPIC has been proposed as a NASA/Discovery mission. The EPIC team, including industrial partners 

Lockheed Martin (telescope & VNC), Ball Aerospace 

(spacecraft bus), and the GSFC Instrument Design 

Center, have conceived a mature design using heritage 

technology (Kepler, Deep Impact) for a Probe class 

mission (< $800 million). The design includes extensive mission- and systems-level engineering down to 

the sub-system/component level, leading to a well-balanced error budget with a low-risk design and realizable mission. EPIC was selected as a NASA Astrophysics Strategic Mission Concept (ASMC) study (FY08/

FY09) and as part of this effort was the only selected 

mission independently costed through both GSFC 

Integrated Design Center (ICD) and JPL’s Team-X, 

thereby achieving high reliability in the cost estimates.

GSFC FY09 IR&D funding enabled demonstration 

of the critical VNC technology to achieve ~108

 contrast in the core of the Airy disk (narrowband). NASA 

FY09 SBIR funding enabled development and delivery of critical component level technology including 

the highest quality MEMS deformable mirror ever 

manufactured, and a high-quality coherent fiber bundle matched to the deformable mirror. GSFC, with its 

industrial partners, developed an incremental suite of 

VNC testbeds, which include the Vacuum VNC, the 

Null Control Breadboard (NCB), and the Compact 

Nuller. 

The Vacuum VNC allows successive validation of 

milestones through ever increasing contrast in succesSTOP analysis of Compact Nuller showing the 

effect of thermal gradients. The largest dimension 

is ~10 inches. 

Schematic view of one design for the EPIC Visible 

Nulling Coronagraph. 

NASA/EPIC

NASA/EPIC

This simulated EPIC image shows our solar system 

as seen face-on from 10 parsecs away. Major planets 

and structure within zodiacal dust disk are evident.NASA/EPIC
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Astrophysics Science Division: Research and Missions

sively broader bands through the use of the deformable mirror, achromatic phase shifter, coherent fiber 

bundle, and successively better null sensing and control. The NCB allows sensing and control algorithm 

development, and the Compact Nuller incorporates 

lessons learned into an athermal kinematic design that 

is cross-validated against a detailed structural, thermal, optical (STOP) model developed by Lockheed 

Martin. Recent selection of the VNC under a NASA 

TDEM (Technology Development for Exoplanet 

Missions, FY10/11) allows the EPIC team to advance 

the TRL from 3 to 4 and achieve 109

 contrast in >15% 

passband and hold it for > 1,000 seconds.

Laser Interferometer Space Antenna (LISA)

The Laser Interferometer Space Antenna (LISA) is a 

joint ESA-NASA project to design, build and operate 

a space-based gravitational wave detector. Space-time 

strains induced by gravitational waves are detected by 

measuring changes in the separation of free-falling 

masses with laser interferometry. Three spacecraft 

form an equilateral triangle with five-million-kilometer-long sides defined by six masses, located in pairs at 

the vertices. Changes in the separations are monitored 

interferometrically to achieve a usable sensitivity in 

the frequency band between 1 × 10-4 and 0.1 Hz

The science objectives of the missions are:

• Understand the formation and growth of massive 

black holes and their host galaxies

• Make precision tests of general relativity and dynamical strong-field gravity

• Explore stellar populations and dynamics in galactic nuclei

• Survey ultra-compact binaries and study the morphology of the Galaxy

• Probe new physics and cosmology

Although the gravitational wave spectrum has not yet 

been explored, LISA is expected to make precision 

measurements of the following sources:

• Merging massive black holes resulting from galaxy 

and proto-galaxy mergers (102

–107 solar masses, z 

< 20, tens to 100 per year)

• Stellar mass black hole inspirals (~10/106 solar 

masses, z < 1, tens to 100 per year)

• Galactic and extra-galactic ultra-compact binaries 

(tens of thousands, confusion foreground)

• Cosmological backgrounds, bursts, and unforeseen sources

The LISA Project Office is at GSFC. The Gravitational 

Astrophysics Laboratory provides the Project Scientist 

(Robin Stebbins), three Deputy Project Scientists (Stephen Merkowitz, Jeff Livas, Jordan Camp), and about 

10 other scientists who support project formulation, 

mission system engineering, technology development, 

risk reduction activities, astrophysical source studies, 

numerical relativity calculations of source waveforms, 

LISA data analysis research, and LISA Pathfinder data 

analysis. 

Goddard scientists support all 

aspects of project formulation, such as 

requirements development and flowdown, 

system analysis, system modeling, design 

of all mission elements, trade studies, and 

document preparation. 

Goddard scientists support all aspects of project formulation, such as requirements development and 

flowdown, system analysis, system modeling, design 

of all mission elements, trade studies, and document 

preparation. Goddard risk-reduction activities include 

The VNC deformable mirror and spatial filter 

array. Left: Photo of SBIR Phase-II developed 

MEMS deformable mirror (uncoated). Diameter 

of black circular region is ~9 mm. Right: Photo of 

custom coherent fiber bundle without lenslet arrays 

mounted.

NASA/EPIC
Astrophysics Science Division: Research and Missions

72

lasers, laser frequency stabilization (including prestabilization and arm-locking), the telescope pointing mechanism, photoreceiver optimization, telescope 

construction, control system modeling, and I&T 

technologies. The numerical relativity group in the 

Gravitational Astrophysics Lab has led the way in producing merger phase waveforms for inspiraling black 

holes, a crucial ingredient in LISA data analysis, and 

predicting LISA’s effectiveness in the estimation of astrophysical parameters of merging sources. Improved 

parameter estimation has shown how the instrument 

performance can be made an order of magnitude larger than previously anticipated.

LISA will be preceded by LISA Pathfinder, an ESA-led 

mission to demonstrate critical LISA technology on 

orbit. LISA Pathfinder carries both ESA and NASA 

instrument packages to demonstrate the Gravitational 

Reference Sensor (proof mass, reference housing with 

electrodes, charge control subsystem, caging subsystem, front-end electronics, and vacuum subsystem), 

drag-free control laws, two types of micronewton 

thrusters, a master oscillator laser, various aspects of 

interferometer construction, and, most importantly, 

the acceleration noise model. LISA Pathfinder is currently scheduled for launch in the first half of 2012. 

The Project has passed its mission CDR, the spacecraft 

is almost completely integrated and the propulsion 

module is complete.

In a new initiative, the Gravitational Astrophysics Lab 

hired James (Ira) Thorpe to support the analysis of 

data from the NASA instrument package, called ST-7 

Disturbance Reduction System, and the ESA instrument package, called the LISA Technology Package. 

Dr. Thorpe has participated in workshops preparing 

for the analysis of data from inflight tests.

Advanced Technology Large Aperture Space 

Telescope (ATLAST)

ATLAST is a concept study consisting of three point 

designs for an 8- to 16-meter UV/optical/NIR observatory designed for operation in a halo orbit at the 

Sun-Earth second Lagrange point (SEL2). ATLAST 

would have an angular resolution 5–10 times better 

than the James Webb Space Telescope (JWST) and a 

sensitivity limit 40–300 times better than the Hubble 

Space Telescope (HST). This concept was selected for 

study by NASA as one of the Astrophysics Strategic 

Mission Concept studies in preparation for the National Academy’s Astro2010 Decadal Survey. Marc 

Postman (STScI) is the Principal Investigator and 

GSFC is the managing NASA Center. Team members include JPL, NGST, Ball Aerospace and scientists 

from the community. ASD scientists involved in the 

study include Mark Clampin, Ted Gull, Rick Lyon, 

Bill Oegerle, Jennifer Wiseman, and Bruce Woodgate, 

as well as a number of people from the GSFC Engineering Directorate. 

The ATLAS Telescope is envisioned as a flagship mission of the 2025–2035 period designed to address 

one of the most compelling questions of our time: Is 

there life elsewhere in our Galaxy? It will have the capabilities required to explore the nearest ~1,000 stars 

capable of harboring life for Earth-size planets and 

characterize their spectra. ATLAST will also be a next 

generation UV/Optical Great Observatory—in the 

model established by HST—that is capable of achieving breakthroughs in a broad range of astrophysics 

and adaptable to addressing scientific investigations 

yet to be conceived. Indeed, such a telescope would 

revolutionize the study of galaxy evolution, enabling, 

for the first time, measurements of the kinematics of 

both the gaseous and stellar components of the smallest dwarf galaxies. It would yield such precise constraints on hierarchical-structure formation models 

that a new era of “precision galaxy evolution” would 

ensue. The superb spatial resolution would also allow 

unprecedented studies of resolved stellar populations 

in nearby galaxies.

The ATLAS Telescope is envisioned as a 

flagship mission of the 2025–2035 period 

designed to address one of the most 

compelling questions of our time: Is there 

life elsewhere in our Galaxy?

Two of the point designs (for an 8m monolithic mirror telescope and a 16m segmented, deployable-aperture telescope) are enabled by NASA’s plans for a large 

Cargo Launch Vehicle (the Ares V), which will have 

a fairing size of 9–10 meters in diameter and the lift 

capacity to take 100 metric tons to SEL2. The 8-meter 

monolith telescope would fit into the Ares V fairing 
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Astrophysics Science Division: Research and Missions

with the secondary fully deployed in an upright position. This eliminates a lot of risk in deployment in 

orbit. The 16m segmented-aperture telescope builds 

on the JWST heritage in terms of its segmented design 

and folded packaging. 

A third point design, being studied primarily at 

GSFC, is for a 9.2m segmented telescope that would 

fit into the fairing of an upgraded Evolved Expendable 

Launch Vehicle (EELV), such as the Delta IV heavy. 

All three point designs are identifying the technology 

investments needed to enable these telescopes, such as 

lightweight mirrors with accurate figures, active wavefront sensing and control, and large-format detector 

technologies, to name just a few. The ATLAST study 

report was delivered to NASA in April 2009 and several reports were submitted to the Astro2010 Decadal 

Survey committee for consideration. Further details 

about the ATLAST mission can be obtained from the 

ATLAST public website www.stsci.edu/institute/

atlast.
Astrophysics Science Division: Research and Missions

74
75

Astrophysics Science Division: Research and Missions

Astronomy Club pitched in to provide a “Telescope Tuneup” workshop, and to hold star parties. The 100 Hours 

project added to the ASD’s existing efforts and EPO 

portfolio by bringing new community partners and 

audiences to the table.

Afterschool Universe continues to expand its network 

of trained providers who run this 12-unit afterschool 

program in local communities. Anita Krishnamurthi, 

Sarah Eyermann (SP Systems), and Sara Mitchell 

(SP Systems) ran six training workshops around the 

country. The team won 2009 NASA Honor Award 

for Public Service Group Achievement for “dedication 

and innovation in bringing NASA into the lives of 

thousands of individuals who might not otherwise be 

engaged in space science.” In addition, the team won 

an Education & Public Outreach for Earth and Space 

Sciences (EPOESS) grant to run a “train the trainer” 

workshop to continue program dissemination in 2010 

and beyond.

Our Blueshift podcast, under the direction of Sara 

Mitchell, is now on a semimonthly release schedule. 

In 2009, we released 23 episodes, including a special 

video episode exploring the hidden corners of Building 2, with over 100,000 downloads. The podcasts 

have tackled a variety of topics, from exoplanets to 

cosmology to technology, while taking listeners behind the scenes in ASD. 

The Big Explosions and Strong Gravity (BESG) program, directed by Ann Hornschemeier (GSFC) and 

Sarah Eyermann, targets Girl Scouts aged 11 to 13. 

This is a one-day event where girls meet real scientists 

VI.Education and Public Outreach 

in NASA’s Astrophysics 

Science Division

E/PO within the Astrophysics Science 

Division

The Astrophysics Science Division supports a strong 

and vibrant Education and Public Outreach (E/PO) 

program. The E/PO team includes members who support various NASA astrophysics missions and programs, including ACE, HEASARC, Webb, GEMS, 

Suzaku, and RXTE. The team also supports a broader 

EPO effort that is not mission specific and covers 

ASD science and technology. The E/PO group was led 

by Dr. Anita Krishnamurthi (CRESST/USRA) until August 31, 2009, after which Dr. James Lochner 

(CRESST/USRA) assumed the duties as Acting E/PO 

Lead.

This past year saw a number of significant events, 

milestones and accomplishments. 

The ASD E/PO group took a lead role in organizing 

Goddard’s participation in the International Year Of 

Astronomy’s 100 Hours of Astronomy from April 2–5. 

We piloted a number of ideas to reach new audiences 

and engage the local community. We also partnered 

with our Goddard Education colleagues in the Education office and in other divisions to hold these events. 

We invited area informal educators for a tour of Goddard facilities and provided a showcase of GSFC-wide 

products and programs for informal settings. We also 

provided a tour and a panel discussion for area guidance counselors, offering them a first-hand view into 

different NASA careers. We offered a “Teacher’s Night 

at Goddard” at the Visitor Center, providing an informal setting for teachers to mingle with Goddard 

scientists, and education professionals, while learning 

about our formal education products and programs. 

We worked with the Friends of Ann Arundel County 

Trails to run a docent-hosted Planet Walk along the 

Baltimore-Annapolis Trail. We provided volunteer scientists from GSFC to staff tables at each of the planets so 

that visitors may learn about the planets and about recent 

the NASA planetary missions. We also provided structured activities for families at the Visitor Center, arranging for Astrocappella to provide entertainment. Finally, 

the Astronomical Society of Greenbelt and the Goddard 

Families participated in ASD-led events at the 

Visitor Center for 100 Hours of Astronomy.
Astrophysics Science Division: Research and Missions

76

It Out,” an online game about the development of 

telescopes and the design of Webb. Masetti also took 

Webb into the world of social media, with accounts on 

Twitter and Facebook, and a YouTube channel. 

HEASARC E/PO

The HEASARC E/PO program continues to fulfill its 

mission of bringing the science of high-energy astrophysics and cosmology to teachers and their students. 

Dr. James Lochner (CRESST/USRA) and Dr. Barbara Mattson (ADNET) completed the HEASARC’s 

“Cosmic Times” project. This set of six posters with 

accompanying lesson plans describes how our knowledge of the universe has changed over the past 100 

years. Each poster mimics the front page of a newspaper with articles about key discoveries in this history. 

The posters were printed mid-year and by end of the 

year more than 1,000 sets had already been distributed. The Cosmic Times web site provides resources 

for teachers, including the lessons and a teacher guide. 

This year, Dr. Lochner and Mattson also revised the 

Cosmic Times web site to include an on-line edition 

of the posters. They also developed a third differentiated version of the poster articles to make the material more accessible to students in grades 7–9. During 

the course of the year, they conducted five workshops 

on the Cosmic Times materials, including an NSTA 

webinar, as well as published an article about Cosmic Times in NSTA’s The Science Teacher, a journal for 

high school teachers. 

and join them for a day of hands-on exploration into 

supernovae and black holes. Girls whose interest in 

science is piqued by this event participate in a followon program, the A.C.E. of Space club (A.C.E. stands 

for Astronomical Cosmic Exploration). This is a girlled club in which the members explore different parts 

of the universe during their meetings over the course 

of a year.

ASD E/PO, as well as a number of our mission E/

PO programs, ventured into social media, establishing 

accounts on Twitter, Facebook, and for Webb a YouTube channel. Our NASAUniverseEdu Twitter feed, 

with tweets composed by Barbara Mattson (ADNET), 

provides information about upcoming workshops, 

facts about our missions, and updates to our web sites. 

We currently have 129 followers. In addition, John 

Mather gave a talk in Second Life on the NASA eEducation Island. It was well attended by avatars from 

around the world!

Using the five-year WMAP results, Britt Griswold 

(Maslow Media) and Gary Hinshaw (GSFC) created 

the second edition of the “WMAP Beach Ball.” More 

than 5,000 were distributed in 2009. (The first edition of the WMAP Beach Ball is part of the set for 

the CBS comedy “Big Bang Theory”.) Mike Greason 

(ADNET), Britt Griswold, and Gary Hinshaw also released “Build a Universe,” a Flash-based game to help 

the public understand how scientists figure out the age 

and content of the universe from the WMAP results. 

For the James Webb Space Telescope, Maggie Masetti (ADNET) completed two new levels of “Scope 

A crowd gathers to hear John Mather’s presentation 

in Second Life.

The Cosmic Times posters
77

Astrophysics Science Division: Research and Missions

The HEASARC E/PO program continues to send 

out our formal education materials to teachers 

and workshop providers. But over the past year we 

branched out to supply our materials to the Night Sky 

Network, an organization run by the Astronomical 

Society of the Pacific consisting of more than 200 

amateur astronomy clubs around the country. These 

clubs have used the Imagine the Universe! CDs not 

only for their star parties and teacher workshops, but 

for other events and audiences such as the National 

Federation of the Blind, a city symphony, more than a 

few senior citizen centers, a summer camp for children 

of incarcerated parents, a 4H group, the Science 

Olympiad training, and a dozen presentations at inner 

city libraries. This has greatly expanded the audience 

for our materials. 

The HEASARC E/PO program successfully obtained 

funding through the Education & Public Outreach 

for Earth and Space Sciences (EPOESS) Program to 

continue the production of the Imagine the Universe! 

CD-ROM. The CD-ROM captures the HEASARC’s 

education web sites, as well as the previous year’s 

Astronomy Picture of the Day pages. The grant will 

not only provide funding for production for three 

years, but also funding to determine more precisely 

the demographics of our audience and how they use 

the CD-ROM.
Astrophysics Science Division: Research and Missions

78

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Standard Form 298 (Rev. 8-98)

Prescribed by ANSI Std. Z39-18 

01-03-2010 Technical Memorandum

Astrophysics Science Division Annual Report 2009

Oegerle, William, and Reddy, Francis, Editors

Astrophysics Science Division

NASA Goddard Space Flight Center 201002611

National Aeronautics and Space Administration

Washington, DC 20546-0001

NASA/GSFC

TM-2010-215853

Unclassified-Unlimited, Subject Category: Astrophysics

Report available from the NASA Center for Aerospace Information, 7115 Standard Drive, Hanover, MD 21076. (443)757-5802

The Astrophysics Science Division (ASD) at Goddard Space Flight Center (GSFC) is one of the largest and most diverse

astrophysical organizations in the world, with activities spanning a broad range of topics in theory, observation, and mission and

technology development. Scientific research is carried out over the entire electromagnetic spectrum—from gamma rays to radio

wavelengths—as well as particle physics and gravitational radiation. Members of ASD also provide the scientific operations for three

orbiting astrophysics missions—WMAP, RXTE, and Swift, as well as the Science Support Center for the Fermi Gamma-ray Space

Telescope. A number of key technologies for future missions are also under development in the Division, including X-ray mirrors,

space-based interferometry, high contrast imaging techniques to search for exoplanets, and new detectors operating at gamma-ray,

X-ray, ultraviolet, infrared, and radio wavelengths. The overriding goals of ASD are to carry out cutting-edge scientific research,

provide Project Scientist support for spaceflight missions, implement the goals of the NASA Strategic Plan, serve and support the

astronomical community, and enable future missions by conceiving new concepts and inventing new technologies.

Astronomical instruments and techniques; radio, gamma-ray, X-ray, ultraviolet, infrared astronomy; cosmology; particle physics;

gravitational radiation; celestial mechanics; space plasmas; and interstellar and interplanetary gases and dust

 Unclassified Unclassified Unclassified

Unclassified

76

William Oegerle

(301) 286-8801