# Presentation: 199048

## A Survey of the Present and Future of Astro/Cosmo/Particle Physics 

- S. Ritz
*ritz@milkyway.gsfc.nasa.gov*
- Introduction and motivation
- Quick (and incomplete) physics survey
- Cultural evolution
- Perspectives and Summary

**Snowmass 2001 July 1**

## Historical connections: fundamental physics and astrophysics

- 1887: Michelson & Morley publish fundamental results on propagation of light - an experimental cornerstone of relativity.

- 1920: Michelson makes the first-ever measurement of the diameter of a star (Betelgeuse) by applying interferometry to astronomy. A new field!

- Laboratory techniques for fundamental physics investigations have long been successfully and fruitfully applied to astrophysical measurements.  These measurements in turn enable us to test and further explore fundamental physics.

## Address fundamental questions, test limits of physical law using most extreme environments, and study the relics from the Big Bang
explore black holes:  acceleration mechanisms producing high-energy jets; goal to study region around event horizon.
find origin(s) of the highest energy cosmic rays
understand gamma-ray bursts
uncover dark matter
study CMB
test Inflation  
search for other Big Bang relics
detect gravity waves
confirm and study the ‘Dark Energy’
Discovery!

- explore black holes:  acceleration mechanisms producing high-energy jets; goal to study region around event horizon.
- find origin(s) of the highest energy cosmic rays
- understand gamma-ray bursts
- uncover dark matter
- study CMB
- test Inflation
- search for other Big Bang relics
- detect gravity waves
- confirm and study the ‘Dark Energy’
- Discovery!

**“****The Universe as a Laboratory”**

## Relation to Snowmass01 Activities

**Relation to Snowmass01 Activities**

**P1             P2              P3             P4             P5**

**EW Symmetry Breaking**

**Flavor**

**Scales Beyond 1 TeV**

**Astro/Csomo/Particle**

**QCD**

- (number of people who signed up for all five groups: 6)

**These tags show related Snowmass sessions.**

## Brief Overview of Physics Topics

**Sort by messenger, energy:**
** **
**Gamma rays, X-rays**
**Optical**
**Microwave**
**Cosmic rays**
**UHE neutrinos**
**Gravity waves**
**Direct searches for dark matter**
** **
** **

## Cosmic -ray Measurement Techniques

- ~103 g cm-2

- ~30 km

- Atmosphere:

- For E < ~ 100 GeV, must detect above atmosphere (balloons, satellites)
- For E > 100 GeV, information from showers penetrates to the ground (Cerenkov, air showers)

- _Energy loss mechanisms:_

## Unified gamma-ray experiment spectrum

- The next-generation ground-based and space-based experiments are well matched.

_**Complementary capabilities**_
**	****	**_**ground-based**__*****__**  space-based**_
- angular resolution	good	         good
- duty cycle		low	         excellent
- area		**HUGE !**	         relatively small
- field of view	small	         excellent (~20% 			                     of sky at any instant)
- energy resolution	good	         good, w/ small
- 			         systematic
- 			         uncertainties

***air shower experiments have excellent duty cycle and FOV, and poorer energy resolution.**

## Unified Gamma-ray Experiment Spectrum

**Unified Gamma-ray Experiment Spectrum**

- “sensitivity”

**See:**
** ****P4 plenaries on 5, 11, 18 July; **
** ****Special topical sessions 9, 10, 11, 12, 13, 18 July;**
** ****Gamma Hikes/Discussions:      ****	****8, 15 July**

## Gamma-ray experiments address a very broad menu of fundamental topics that include:
Systems with supermassive black holes
Gamma-ray bursts (GRBs)
Dark Matter
Probing the era of galaxy formation
Discovery!  -- the new experiments have huge increments in capabilities

These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**Systems with supermassive black holes**
**Gamma-ray bursts (GRBs)**
**Dark Matter**
**Probing the era of galaxy formation**
**Discovery!  -- the new experiments have huge increments in capabilities**
- These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**The BIG Picture**

- Active Galactic Nuclei (AGN) are immense accelerators, probably powered by ~billion solar-mass black holes.  Many shine most brightly in gamma rays, which diagnose the accelerated jets of particles.

**VERITAS will**
**measure short-**
**term variability**
**with dramatically**
**better precision**

- Contemporary experiments (Whipple,
- STACEE, CELESTE, EGRET, ...) together study a few to dozens of AGN.  Expect GLAST to improve on this by two orders of magnitude:

**EGRET 3****rd**** Catalog: 271 sources**
**GLAST 1****st**** Catalog: expect >**_**9000 sources**_

## Gamma-ray experiments address a very broad menu of fundamental topics that include:
Systems with supermassive black holes
Gamma-ray bursts (GRBs)
Dark Matter
Probing the era of galaxy formation
Discovery!  -- the new experiments have huge increments in capabilities

These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**Systems with supermassive black holes**
**Gamma-ray bursts (GRBs)**
**Dark Matter**
**Probing the era of galaxy formation**
**Discovery!  -- the new experiments have huge increments in capabilities**
- These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**The BIG Picture**

## Gamma-ray experiments address a very broad menu of fundamental topics that include:
Systems with supermassive black holes
Gamma-ray bursts (GRBs)
Dark Matter
Probing the era of galaxy formation
Discovery!  -- the new experiments have huge increments in capabilities

These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**Systems with supermassive black holes**
**Gamma-ray bursts (GRBs)**
**Dark Matter**
**Probing the era of galaxy formation**
**Discovery!  -- the new experiments have huge increments in capabilities**
- These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**The BIG Picture**

- If the SUSY LSP is the galactic dark matter there may well be observable
- halo annihilations into mono-
- energetic gamma rays.

- q

- q

- or  or Z

- “lines”?

- X

- X

**Just an example of what might be waiting for us to find!**

## Gamma-ray experiments address a very broad menu of fundamental topics that include:
Systems with supermassive black holes
Gamma-ray bursts (GRBs)
Dark Matter
Probing the era of galaxy formation
Discovery!  -- the new experiments have huge increments in capabilities

These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**Systems with supermassive black holes**
**Gamma-ray bursts (GRBs)**
**Dark Matter**
**Probing the era of galaxy formation**
**Discovery!  -- the new experiments have huge increments in capabilities**
- These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**The BIG Picture**

## Gamma-ray experiments address a very broad menu of fundamental topics that include:
Systems with supermassive black holes
Gamma-ray bursts (GRBs)
Dark Matter
Probing the era of galaxy formation
Origin of Cosmic Rays
Discovery! (Hawking Radiation?  Using Bursts to detect photon velocity dispersion?  Other relics? ...     -- huge increments in capabilities

These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**Systems with supermassive black holes**
**Gamma-ray bursts (GRBs)**
**Dark Matter**
**Probing the era of galaxy formation**
**Origin of Cosmic Rays**
**Discovery! **(Hawking Radiation?  Using Bursts to detect photon velocity dispersion?  Other relics? ...    ** -- huge increments in capabilities**
- These experiments draw the interest of both the the High Energy Particle Physics and High Energy Astrophysics communities.

**The BIG Picture**

## Information from Xrays

**Xray astrophysics is in a particularly productive period, driven by Chandra and XMM-Newton:**
**The plans for the future are remarkable**

- "NASA/CXC/SAO"

- early Chandra image
- of the Crab nebula

- Chandra is optimized for high spatial resolution (~0.25”) and spectral resolution.
- XMM is optimized for large collecting area (~2500 cm2) and field of view.

## Roadmap to Image a Black Hole in Xrays

**Roadmap to Image a Black Hole in Xrays**

***2000***

***2008***

***2014***

***2020***

***Imaging***

***Spectroscopy***

***1000 times finer imaging***

**MAXIM **
**Pathfinder**

***X-ray interferometry***
***first flight***

***Black hole imager!***

**MAXIM**

***10 Million times finer imaging***

***Conditions in the inner disk***

**Constellation-X**

***100 times larger  area***

***Optimize MAXIM Parameters***

***Find them***

## Xray Interferometry

- Webster Cash et al(1999) have built a modern xray interferometer:

- 16 m

- ~0.6mm

- ~17mm

- 100 m

- Extrapolating...

- see: Nature, Volume 407, Issue 6801, pp. 160-162 (2000)

## The Black Hole Imager: MAXIM Observatory Concept

- 32 optics (300  10 cm) held in phase with 600 m baseline to give
- 0.3 micro arc sec
**34 formation flying spacecraft**

**1 km**

**Optics**

- 10 km

**Combiner **
**spacecraft**

** ****500 km**

**Detector**
**spacecraft**

***Black hole image!***

***System could be adjustable on orbit to achieve larger baselines***

- See Nick White’s talk on Cosmic Journeys, 12 July

## Optical

**Optical**

**Use type Ia Supernovae corrected candles to measure the expansion rate.  Ground-based work thus far has uncovered a major surprise:**

## Optical

**Use type Ia supernovae corrected candles to measure the expansion rate.  Ground-based work thus far has uncovered a major surprise:**

**Similar results from**
**the High-z Supernova**
**Search Team (e.g.,**
**Riess et al AJ116(1998))**

## Implications

**Implications**

**Contrary to expectation, the expansion of the Universe appears to be **_*increasing*_** with time!**

- This could be due to a non-zero cosmological constant, a manifestation of non-zero vacuum energy....

- ... or systematic effects yet to be understood.
**This result has raised fundamental questions and begs further investigation.**

## PROPOSAL: Large statistics, ~2000 Sne Ia’s, distributed in redshift to z<1.7, with minimal selection bias and clean Ia ID.
Key is systematic error reduction: 
Discover SNe 3.8 mag before max, 10 points on lightcurve
Near-IR spectroscopy to 1.7 m
Guess

=> Investigate w(z)=p/

**PROPOSAL: Large statistics, ~2000 Sne Ia’s, distributed in redshift to z<1.7, with minimal selection bias and clean Ia ID.**
_**Key is systematic error reduction**_**:**** **
- Discover SNe 3.8 mag before max, 10 points on lightcurve
- Near-IR spectroscopy to 1.7 m
**Guess**
**=> Investigate *****w*****(z)=p/******

**What Is Needed Next?**

## SNAP Instrument Concept

**SNAP Instrument Concept**

_**2m aperture telescope**_
_**Optical photometry**_** with 1****°x ****1****°**** billion pixel mosaic camera, high-resistivity, rad-tolerant p-type CCDs sensitive over 0.35-1 ********m**
_**IR photometry**_** 10’x10’ FOV, HgCdTe array (1-1.7 ********m)**
_**Integral field**__** **__**optical and IR spectroscopy**_** 0.35-1.7 ********m, 2”x2” FOV**

_**11 July**_**: Status of Dark Energy Experiments**
_**14 July**_**: Future of Dark Energy Experiments**

_**Concept is evolving**_.  Collaboration is
- seeking input from all interested communities.
_**“**__**Collaboration is open**_.”

## Recent Related Results

** ****A serendipitous discovery (Riess et al, astro-ph/0104455) of a supernova at z=1.7 (in the “decelerating” era) reduces the likelihood that gray dust fakes the apparent acceleration.**
** ****The SN light curve broadening is consistent with that expected from cosmological expansion:**

**excludes “tired light” hypothesis**
**by  18 ******

**w = s(1+z)**

## Sloan Digital Sky Survey

-  Large-scale structure survey
-  Map position and redshift of more than 1 million galaxies and 100,000 quasars (to z ~ 6).
-  International collaboration of astronomers, astrophysicists and particle physicists.  Project Scientist: Jim Gunn; Scientific Spokesperson: Mike Turner; Director is John Peoples
-  Operations started 4/2000
-  Full survey will take ~6.5 years
-  First early major data set released in June 2001

- See P4 sessions: July 14 & 17

**Apache Point dedicated 2.5m telescope**

- ref: http://www.sdss.org/

## SDSS Early Data Release 

**SDSS Early Data Release **

- 500 sq deg of the sky, 14 million objects, spectra for 50,000 galaxies and 5,000 quasars.

**Distance record-holder**

- >13,000 quasars (26 of the 30 most distant known)

- ARP 240
- (NGC 5257/58)
- interacting
- pair of
- galaxies

## Cosmic Microwave Background

**Recent results add to the growing collection of measurements from the ground, balloons, and space:**

- Amazing that we can see this – foreground removal!
- See http://www.astro.ucla.edu/~wright/intro.html
- and http://www.hep.upenn.edu/~max/ and links therein

## Cosmic Microwave Background

**Expected ****MAP**** precision shown as the gray band.  **_**Launched Saturday!**_

**Entering the era of precision cosmology.  Many experiments (e.g., PLANCK, PIQUE, ...) over the next decade will measure the strength of higher acoustic peaks and polarization anisotropy. **

**COBE**

**BOOMERanG**

**MAXIMA**

**CBI**

**TOCO**

**See activities of P4.3, E6.1 (6&7 July) and talk by B. Winstein        (13 July).**

## Cosmic rays: two big questions

**Cosmic rays: two big questions**

**What are the acceleration mechanisms?  **
**How do cosmic rays propagate through the galaxy?**

- Propagating cosmic rays above the _GZK energy_ interact with the bath of CMB photons.

- so what are these??

**O(1) particle/km****2****/century above 10****20**** eV**
**Corresponds to 16 J of KE in ONE particle**

- compilation: S. Swordy 1997

**(soon to be out-of-date: stay tuned for HIRES results at ICRC in August)**

## UHE Cosmic Ray Techniques

- _Nitrogen Fluorescence_

- _Air Shower_

- See P4 and E6 sessions July 5, 10, 17

| Experiment | Technique | Eff.  Aperture [1000xkm^2-sr] | Status |
| --- | --- | --- | --- |
| AGASA | Ground Array | ~0.2 | running |
| HiRes | Fluor. | ~1 | running |
| Auger | Ground Array + Fluor. | 7
( x2) | building
(prop) |
| Telescope Array | Fluor. | 8 | under study |
| OWL | Fluor. | ~300 | under study |

**OWL**

## Alpha Magnetic Spectrometer

**See http://ams.cern.ch/AMS/ams01_homepage.html **

**An experiment to search in space for dark matter, missing matter & antimatter on the international space station. **
**Successful shuttle experiment flight of AMS1 in June 1998.**
**Manifested on shuttle flight to the ISS in 2005. **

**See talks 5 and 17 July**

## Cosmic Ray Composition: ACCESS

**Cosmic Ray Composition: ACCESS**

**Explore the cycles of matter and energy **
**in the evolving universe**** **
**  ****How are cosmic rays accelerated?**
- What are the source energy spectra?
- Measure changes of individual element spectra taken
- 	at maximum energies expected from supernova
- 	shock acceleration
**  ****How do cosmic rays escape from the Galaxy?**
- Measure energy dependence of abundance of
- primary and  “spallation” nuclei
**Measurement Goals**
-   **Measure ~ 30 times more p, He events than Japanese **
**   ****American Cooperative Emulsion Experiment (JACEE)**
**   ****balloon fights (1979 - 1995)**
- 	Extend p and He spectra from 200 TeV to 1000 TeV
-   **Measure ~ 3000 times more Z > 4 events than CRN **
**   ****Shuttle  flight of 1985. **
- Extend carbon spectrum from 20 TeV to 1000 TeV
- Extend iron spectrum from 80 TeV to 5000 TeV

- Status: Formulation study completed.
- Proposal in preparation.
- Plan to deploy in 2007/08.

## High Energy Neutrino Astronomy

| Experiment | Where | Status |
| --- | --- | --- |
| DUMAND | Hawaii | pioneer, defunded |
| BAIKAL | Siberia | limits on WIMPs, monopoles |
| AMANDA | South Pole |  hundreds of atmospheric events reconstructed from 97 running – technique understood.
 results w/ limits on fluxes from GRBs, AGN, WIMPs, point sources.
 First year of data from AMANDA – II being analyzed. |
| NESTOR | Greece | prototype studies |
| ANTARES | France | prototype running |
| IceCube | South Pole | under review |

- summary courtesy Doug Cowen

**A new way to observe the cosmos.  **
**UHE neutrinos (>10****14**** eV) will tell us about **
** ****AGN, Gamma-ray Bursts, UHE Cosmic Rays, ...**
** ****Signatures from WIMPs, topological defects, and other relics.**

**See sessions on  July 10, 11 **

## Gravitational Radiation

**Gravitational Radiation**

***Orbiting and merging massive objects emit gravitational radiation***

- Two biggest experiments aiming to detect gravity waves:

**LISA** (space-based, under development)

**LIGO** (ground-based, under construction)

**first-lock at Hanford  **
**Oct 2000**

- 4 km

## LISA and LIGO are Complementary

**LISA and LIGO are Complementary**

## LISA Mission Concept

**Each of 3 spacecraft:**
- • Mass: 265 kg • Power: 200 W
- • Thrusters: 100 μN Field Emission Electric Propulsion units
**MEASUREMENT CAPABILITIES**
- • Length accuracy: 1 pm in 1000 sec integration
- • Best strain sensitivity:10-23 from 0.003 Hz to 0.010 Hz for 1 year int.
- • Frequency range: 10-4 to 1 Hz
- • Angular resolution: 1 arc minute for strongest sources
**INSTRUMENTATION**
*Each Spacecraft contains two optical assemblies, including:*
- • 30 cm, f/1, transmit and receive telescope
- • Optical bench with interferometer optics, laser stabilization cavity
- • Inertial sensor with free-floating test mass, electrostatic sensing
- • 1 W laser, diode-pumped, Nd: YAG. plus spare
- • Fringe tracking and timing electronics
- •Ultrastable oscillator
- • Laser phase measurement system for intercomparing
- fringe signals from two arms
**MISSION**
- • Joint development of NASA and ESA
-  Launch ~2010

**LISA Mission Concept**

## Other ground-based gravity wave interferometers:

**VIRGO** (France/Italy) http://www.virgo.infn.it/ ,
**GEO600** (Germany/UK) http://www.geo600.uni-hannover.de/
**TAMA300** (Japan) http://tamago.mtk.nao.ac.jp/
**ACIGA** (Australia) http://www.anu.edu.au/Physics/ACIGA/

**See P4 sessions on**
**3, 9, and 16 July**
**[both ground-based and space-based]**

## Direct Searches for Dark Matter: WIMPS

**Direct Searches for Dark Matter: WIMPS**

- LSP in SUSY models continues to be compelling Dark Matter candidate
- decade-long (or longer) efforts paying off: now probing interesting regions of parameter space (always highly model-dependent!)
- systematics/backgrounds!      => broad range of techniques
- proven technologies producing results with excellent near-term prospects for improvements; many new technologies (including directional sensitivity) reaching maturity.

**DAMA annual-modulation result**

**CDMS 90% exclusion**

**Gaitskell and Mandic, http://dmtools.berkeley.edu/limitplots**

**See sessions on 6, 7, 9 and 18 July (P4 and E6)**

- (plot courtesy of Richard Schnee)

## Direct Searches for Dark Matter: Axions

- see http://www-phys.llnl.gov/N_Div/Axion/axion.html and
- reference therein

- http://pdg.lbl.gov/2000/axion3_s029.pdf

- 1st generation exps

**see session on  18 July**

## And Yet More....

**Proton Decay:  See special joint session 17 July **

**Early Universe and Tests of Fundamental Physics sessions:  **
**2, 9, 14 July**

**Special session on European and US Underground Initiatives: **
**3 July**

## Community Connections

**Connections Group** of physicists, astronomers, and space scientists.  Work based upon the input from the community at workshops and conferences [Inner Space/Outer Space (Fermilab, May 1999), Cosmic Genesis (Sonoma State University, November 1999), and Beyond the Standard Models (Aspen, February 2000)], as well as working sessions of the Connections Group.  See _[http://www.](http://www.quarkstothecosmos.org/)__[quarkstothecosmos](http://www.quarkstothecosmos.org/)__[.org](http://www.quarkstothecosmos.org/)_

**Committee on Physics of the Universe** (M. Turner, Chair)
- See http://www.nationalacademies.org/bpa/projects/cpu/
**“****Decadal” Survey** (C. McKee and J. Taylor, Co-chairs)
- See http://books.nap.edu/books/0309070317/html/index.html

**DOE/NSF HEP Subpanel on Long Range Planning for U.S. High Energy Physics **(J.Bagger and B.Barrish, co-chairs)   See http://hepserve.fnal.gov:8080/doe-hep/lrp_panel/index.html

## Let’s make the multi-agency process efficient ...

- A. Michelson, 1887

- A. Michelson, 1928

**Let’s make the multi-agency process efficient ...**

## Astro/Cosmo/Particle Physics at Snowmass

** ****check web pages (and links to subgroups) for schedules:**
** ****P4:  http://pancake.uchicago.edu/~snowmass2001/ **
** ****E6: http://sdss4.physics.lsa.umich.edu:8080/~snowmass2001/**
**Note: every P4 meeting starts with two, one-hour general-interest talks, followed by parallel working group sessions.**
** ****Teach-in: 13 July afternoon:**
- 30-minute introductory talk
- 2-hour interactive physics “carnival” with 6 topic stations.  Come with questions, listen to discussions.
- wrap-up panel discussion

## Summary: Cosmic Messengers

- photons [eV]

- 10-5

- 10-3

- 10-1

- 10

- 102

- 104

- 106

- 108

- radio  | wave |          IR          |v|                   UV           |       x rays      |         rays

- pulsars, AGN, ?

- CMB

- supernovae, starburst,
- galaxy formation &
- dynamics, dark energy

- supernova remnants, accreting systems, stars, dark matter?

- GRBs, AGN, pulsars, SNRs, interacting cosmic rays, DM annihilations?, relic decays?

- 10-3

- 1

- 103

- 106

- 109

- 1012

- 1015

- 1018

- 1021

- hadrons, leptons [eV]

-  mass?

- [big bang relic 

- solar ,
-   SNe 

- cosmic rays (p, e, ...)

*who ordered those??*

- GZK

- UHE neutrinos (AGN, GRBs,...?)

- + gravitons: massive binary systems, GRBs?, early Universe, ...  ????

- new stuff, relics [eV]

- 10-3

- 1

- 103

- 106

- 109

- 1012

- 1015

- 1018

- 1021

- axions?

- sleptosquarkinos?, LSP dark matter?

- primordial black holes?[1015g]

- topological defects?
- proton decay?

- Lyman alpha
- cosmology

- ? ? ? ? ? ? ? ? ? ?

## Perspective

**A wide range of interesting and exciting questions at the interface between Particle Physics and Astrophysics.**
** ****Relics offer leaps forward in our ability to explore Nature.  Example:**
- At the turn of the 20th century, in less than 15 years the smallest distance scale explored shrank dramatically from 10-10 m to 10-14 m.  The discovery of natural radioactivity, a phenomenon from a much higher energy scale than was otherwise accessible at the time by artificial means, made this possible.
**	****Nature offers us these clues to fundamental physics – we just have to be clever enough to look around for them.**