bluuebunny/crossref_metadata_2025 huggingface dataset:
Uncertainties in the Tully-Fisher Method, and a Philosophical Remark
Authors: Sullivan W. T.
Published: March 2016

Studies are now in progress on the nature of various possible systematic and random errors which may be influencing the values of the Hubble parameter Ho derived from application of the Tully-Fisher method to samples of cluster spirals outside of the Local Supercluster. Three effects seem to be of most importance. (1) Clusters yield slopes in the infrared Tully-Fisher diagram varying from 8 to 12, making it problematic as to how to derive a relative distance modulus from comparison with the local calibrators, (2) errors in measured 21-cm line widths (often measured at low signal-to-noise ratios) are the dominant source of error in derived relative distances, (3) errors in measured optical major and minor axes of a galaxy influence both its derived inclination and the H-magnitude as corrected to a standard isophote. Monte Carlo simulations of cluster samples, however, have shown that the tendency not to detect H I from edge-on and/or low-luminosity galaxies introduces no important biases. Overall, the relative distance of any of these clusters to the local calibrators appears to be good to ±20%.
Kiloparsec Scale Radio Structure in Active Galaxies
Authors: Wilson A. S.
Published: March 2016

A substantial fraction of active galaxies contain linear radio sources with sizes of a few hundreds or thousands of parsecs. Such sources are found in essentially all classes of active galactic nuclei, including Seyfert galaxies of both types, X-ray selected active nuclei, radio galaxies and quasars. The radio emission is clearly energised by the active nucleus, probably in the form of a jet. A number of observable consequences of the interaction of the jet with the interstellar medium of the galaxy are discussed. These processes include jet disruption by instabilities, acceleration of cosmic rays by shocks or turbulence, ionization and radial acceleration of interstellar clouds, creation of a hot thermal component through the agency of shock waves and bending of the jet by the ram pressure of a rotating interstellar medium.
X-Rays from Active Galactic Nuclei
Authors: Fabian A.C.
Published: March 2016

Recent X-ray observations of active galactic nuclei and Seyfert galaxies in particular are briefly reviewed. The application of the efficiency limit to rapidly varying luminous sources such as NGC 6814 is discussed. It is argued that the variability and probable MeV spectral turnover imply that most of the electrons which radiate the observed flux are only mildly relativistic. A possible link between the steep soft X-ray spectra and featureless optical continua of BL Lac objects is considered.
UV Properties of Symbiotic Stars
Authors: Kafatos M.
Published: March 2016

Symbiotic stars are suspected to be binary systems of large dimensions in which one star is a cool primary giant (regular M-giant or Mira-type variable) and the secondary a hot subdwarf (Boyarchuk 1982) or even a main-sequence star with an accretion disk around it (Bath and Pringle 1982). Observations of symbiotic stars in the far ultraviolet with the “International Ultraviolet Explorer” (IUE) enable us to determine the properties of the system in the binary picture. A number of critical observations are needed to do this including an estimate of the photoionizing radiation and the temperature of the photoionizing source.
Observations of Mass Flow, Disks, and Accretion Processes in Algol Binary Systems
Authors: Peters Geraldine J.
Published: March 2016

As part of a multi-faceted study of gas streams, disks, and accretion processes in Algol type binaries, R.S. Polidan and I have obtained high resolution IUE observations of seven systems. Perhaps one of the most interesting results from these observations was the discovery of strong, variable absorption lines of N V, C IV, and Si IV in the spectra of stars whose photospheres are much too cool to form these ions. N V (1239,1243) and C IV (1548,1551) have been observed in AU Mon (B5V, 11ḍ1), CX Dra (B3V, 6ḍ7), and U CrB (B4V, 3ḍ5) while Si IV (1394, 1403) was found in TX UMa (B8V, 3ḍ1). The systems in which these ions have been observed generally contain primaries whose dimensions are greater than the Lubow and Shu (1975) parameter ϖmin.

Radial velocity measurements of the N V, C IV, and Si IV features suggest that the line formation region is associated with the primary star and small in size. The strengths of the N V, C IV features appear to be variable on a time scale of several orbital periods and may be determined by the instantaneous rate of mass transfer. However, when the high ionization features are observed, their presence appears to be global and not restricted to the domain of gas stream impact.
Recent Developments in Atomic Transition Probabilities
Authors: Wiese W. L.
Published: March 2016

In the last decade, research to determine atomic transition probabilities has proceded at a steady pace. Currently, the main needs for transition-probability data arise from astrophysics, magnetic fusion-energy research, and laser development. The principal approaches for the determination of data have undergone further refinement and the major conventional techniques generally contribute data in roughly the same proportions as earlier. However, some significant changes have also occurred: theoretical approaches, especially semi-empirical approximations, have produced vastly increased amounts of data; on the experimental side, determinations of atomic lifetimes by beam-foil spectroscopy have shown a decline, but work utilizing the branching-ratio emission technique as well as lifetime techniques involving laser excitation are on the increase.
Nutation and reference frame
Authors: Capitaine N.
Published: March 2016

The reference frames are of fundamental importance in all kinds of the precession and nutation studies involving the theory, the coordinate transformation and the observations. The aim of this paper is to review all the frames used in such studies and to lead to a better consistency between them in order that theory and reductions of observations be referred, as close as possible, to the frames to which observables are actually sensitive.

The equations of Earth rotation can be expressed either as Euler equations in the Terrestrial Reference System (TRS), or as perturbation theory in the Celestial Reference System (CRS) (Kinoshita 1977). Euler equations are transformed to the CRS in the astronomical approach (Woolard 1953) and solved by the method of variation of the parameters, whereas, in the geophysical approach (Melchior 1971), the solutions, first obtained in the TRS, are transformed to the CRS and then solved by an integration with respect to time.
Frequencies and splittings of low-degree solar p modes: Results of the Luminosity Oscillations Imager
Authors: Appourchaux T.
Published: March 2016

The design of the LOI instrument was an original idea of Andersen et al. (1988). It consists of a Ritchey-Chrétien telescope (f=1300 mm) imaging the Sun through an 5-nm passband interference filter at 500 nm. The image is projected on a photodiode array detector built to our specifications (Appourchaux et al., 1992). The detector is made out of 12 scientific pixels and of 4 guiding pixels. The shape of the scientific pixels are trimmed to detect low degree modes for l < 7 (Appourchaux and Andersen, 1990). The guiding pixels are 4 quadrants of an annulus with an inner and outer radius of 0.95 and 1.05 solar radius, respectively.
Hydrogen Line Profiles
Authors: Hubeny I.
Published: March 2016

Observed hydrogen line profiles are an enormously important source of diagnostic information about virtually all kinds of astronomical bodies. Therefore, it is important to understand the hydrogen line formation in sufficient detail to be able to achieve a high degree of reliability by analyzing observed hydrogen line profiles.

Calculation of the predicted hydrogen line profiles involves two basic ingredients, (i) intrinsic line profiles, or line broadening - ”atomic physics” part, and (ii) the radiative transfer problem - ”astrophysics” part. There is not enough space to discuss here the current status of the astrophysical part of the problem. Fortunately, this topic is covered by many reviews. There are two major problems here, (a) departures from local thermodynamic equilibrium (LTE) - the so-called non-LTE description (e.g. Mihalas 1978; Hubenyet al.1994); and (b) departures from complete frequency redistribution (Cooperet al.1989; Hubeny and Lites 1994).
Interpretations of Stellar Spectra: NLTE Effects
Authors: Pavlenko Yakiv V.
Published: March 2016

To solve the system of statistical balance equations and radiative transfer equations (NLTE problem) we followed the modification of linearization method proposed by Auer and Heasley (1976) and used 20-level model of the lithium atom. The 70 radiative and all possible collisional transitions were included into the rate matrix (Pavlenko 1994).
Lithium-6 Nucleosynthesis in the ISM
Authors: Malaney Robert A.
Published: March 2016

The nucleosynthesis of 6Li in the galaxy has become of considerable interest in the past year. This is largely because of the exciting developments relating to the first detection of this isotope outside of our own solar system. Not only has 6Li been recently detected in the atmospheres of halo dwarfs [1-2], but also in the local interstellar medium (ISM) [3-4].

It is well known that knowledge of the primordial abundance of the lithium isotopes has important ramifications for cosmology, through the constraints they impose on standard big bang nucleosynthesis (SBBN) [5], and those imposed on non-standard primordial nucleosynthesis models. Since a complete understanding of the galactic evolution of the lithium isotopes is a prerequisite to unambiguously determining their primordial abundance, a thorough interpretation of the new 6Li data in the context of chemical evolution models cannot be overstated.
How Massive is the Black Hole in M87?
Authors: Chakrabarti S.K.
Published: March 2016

Using the Faint Object Spectrograph (FOS) on Hubble Space Telescope (HST), Harms et al. (1994, H94) have recently reported the spectroscopy of central region of the elliptical galaxy M87. Ford et al. 1994 (hereafter F94), using Wide Field Planetary Camera-2 have imaged the region around the nucleus in Hα+[NII] and find an ionized disk with spiral structures of mainly two arms. From the kinematical argument, based on the Doppler shifts of several lines emitted from the disk, and assuming a Keplerian motion of the emitting gas, they conclude that the mass of the disk plus the nucleus: Mc(R < 18pc) = (2.4± 0.7)× 109M⊙ and the inclination angle of the disk with the line of sight is i = (42±5)°. However, if the bright spiral structures are real, and represent shocked region in the disk, we expect that the disk is strongly non-Keplerian and therefore the mass of the black hole must be higher than above estimation.

In the present contribution, we provide a complete description of the velocity field of the ionized disk and compute the shape of typical line profiles expected from various parts of the disk. Our analysis is based on the solution of a non-axisymmetric disk which includes two armed spiral density waves. We find a very good agreement between the theoretical and observed line profiles as regards to the Doppler shifts, line widths and the intensity ratios and estimate the mass of the black hole to be (4 ± 0.2) × 109M⊙. Details of this work will be published elsewhere (Chakrabarti, 1995).

In a binary system with a thin accretion disk, the binary companion can induce two armed spiral shocks in the disk (e.g., Matsuda et al. 1987, Spruit 1987, Chakrabarti & Matsuda, 1992). In the case of active galaxies, a passing companion (or a globular cluster or a dwarf galaxy) which is more massive than the disk can induce the same effect.
High-Redshift Radio Galaxies
Authors: Miley George
Published: March 2016

Radio galaxies are unique cosmological probes. As with radio-loud quasars, the presence of luminous radio continuum and optical line emission enable radio galaxies to be observed and recognized at large distances, up to z = 4.2. However, unlike the situation for most quasars, their optical emission can be spatially resolved from the ground and studied in detail.

Progress in detecting distant radio galaxies has been rapid in recent years due to the use of CCDs and the exploitation of new selection criteria. Now, more than 60 radio galaxies are known with z > 2. More than half of these have been found by our group by concentrating on radio sources with the steepest spectra, most of these in a “Key Programme” of the European Southern Observatory. Although several people contributed to this Key Programme, most of the work was done by Huub Röttgering, who presented his Ph.D thesis in January and Rob van Ojik, who succeededhim. Redshifts of 1.5 to 4 correspond to a time when the Universe was 10% -20% of its present age. This was a crucial period in history when galaxy formation must have been rampant. It corresponds to the AGN era, a two-billion year “delta function” in the population evolution of luminous quasars and radio galaxies, when their space-density rose to a value several hundred times larger than the present density before the species mysteriously and suddenly became almost extinct.
Bars as Triggers of Gas Inflow
Authors: Athanassoula E.
Published: March 2016

I briefly discuss the flow of gas in and around bars and the amount of inflow it entails. I then focus on two ways of bringing gas very near the center of a barred galaxy. One relies on the absence of an inner Lindblad resonance and the other on the existence of bars within bars.
Agns: Demography and Remnants
Authors: Rees Martin J.
Published: March 2016

In this contribution I shall first briefly review the arguments suggesting that most galaxies pass through a quasar or AGN phase early in their lifetime, perhaps concurrent with bulge formation. Then, as a footnote to the paper by van der Marel, I will discuss how relic black holes in quiescent galaxies could reveal themselves by the occasional flares resulting from tidal disruption of stars. In conclusion, I shall briefly discuss the phenomena associated with binary black holes, arguing that these are the likely outcome of galaxy mergers.
Summary of the IRON and OPACITY Projects
Authors: Berrington Keith A.
Published: March 2016

Considerable effort has been made recently by international collaborations, exploiting advances in atomic physics and in supercomputing, to compute complete sets of accurate data for astrophysically important processes; in particular, the Opacity Project and the IRON Project.

The Opacity Project computed atomic data for opacity calculations

• for H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, S, Ar, Ca, Fe.

• energies of terms having effective quantum numbers v≤10 and total angular momentum L≤3 or 4, all spin and parity combinations;

• gƒ-values for all dipole transitions between these bound terms;

• total cross sections for photoionizaion from all calculated bound terms, tabulated on a grid of photon energies suitable to describe the resonance structure in sufficient detail to calculate reliable opacities;

• line broadening parameters.

28 key research papers arising from the Project, together with calculated energies and oscillator strengths for light ions, are reprinted in ‘The Opacity Project Volume 1’ (Opacity Project Team, 1994, IOP Publ. ISBN 0 7503 0288 7). All data are available from TOPbase, an on-line database at the CDS (Cunto et al. 1993, A&A 275, L5).

The IRON Project aims to systematically compute electron excitation cross sections for the iron group of elements. Particular attention is given to requirements for the interpretation of data from specific space observations.

In the first stage of the Project excitation cross sections have been computed for fine-structure transitions in the ground configuration of all ions of astrophysical interest. These data are essential for the interpretation of IR lines to be observed by ISO, as well as for coronal spectra.
Through a Glass Darkly: The Status of Archiving Astronomical Spectra
Authors: Griffin R.E.M.
Published: March 2016

Astronomical research comprises a curious mixture of team work and individualism. From the hardware point of view data are ends in themselves, while from a strictly scientific aspect their acquisition is but the first stage in the complicated process of building astrophysical models. This dichotomy is reflected in a polarization of attitudes regarding the handling of observational data, and the activity of creating archives of astronomical data for use by posterity has consequently tended to fall in no-man’s-land. To the technology team, a telescope that can successfully deliver a data-bank full of raw observations has achieved its specification, while to the scientist who is under pressure to publish papers on fresh science, the concept of voluntarily creating public archives out of data originating from personal ideas may seem more than a little alien. Nevertheless, the formation of useable and efficient archives of astronomical observations is an activity that has taken on new meaning with the advent and monopoly of digital detectors; it is a procedure that builds bridges as well as access routes and it opens new global perspectives for astronomical data, but it still relies too heavily on individual initiatives.
Jupiter’s Synchrotron Radiation Throughout the Comet P/Shoemaker-Levy 9 Impact Period
Authors: de Pater I. , Heiles C. , Wong M. , Maddalena R.J. , Bird M.K. , Funke O. , Neidhoefer J. , Price R.M. , Kesteven M. , Calabretta M. , Klein M.J. , Gulkis S. , Bolton S.J. , Strom R.G. , LePoole R.S. , Spoelstra T. , Robison M.
Published: March 2016

Jupiter’s microwave emission was observed throughout the SL9 impact period by many different telescopes, among which the NRAO 140-foot telescope in Green Bank (21 cm), Westerbork (92 cm), Effelsberg (6, 11 cm), Parkes (21 cm), NASA DSN (13 cm), and the Very Large Array (22, 90 cm). We determined the “average” total nonthermal flux density from the planet after having subtracted the thermal contribution, following the formulation by de Pater and Klein, (1989) and Klein et al., (1989). The flux density increased typically by 40-50% at 6 cm wavelength, 27% at 11-13 cm, 22%at 21 cm and 10-15% at 90 cm. Thus the radio spectrum hardened considerably during the week of cometary impacts. Following the week of cometary impacts, the flux density began to subside at all wavelength.

VLA images show the brightness distribution of the planet; a comparison of images taken before and during the week of impacts show marked changes in the brightness distribution. At a central meridian longitude λIII≈ 110°, the left side of the belts increased considerably and moved inwards by ~ 0.2 RJ. This suggests that the increase in flux density is caused by energization of the resident particle population.
The Three-Dimensional Structure of Our Galaxy
Authors: Perryman M.A.C.
Published: March 2016

This presentation has the following goals: (i) to explain, within a historical context, some of the difficulties in disentangling our Galaxy’s three-dimensional structure; (ii) to summarise in broad terms what we presently know of this structure, concentrating on those features inferred from accurate distance measurements; (iii) to illustrate selected aspects in a visually stimulating manner; and (iv) to give a foretaste of the exciting results that lie ahead with future space astrometric experiments.
Overview of Mid-Infrared Observatories
Authors: van Dishoeck Ewine F.
Published: March 2016

A brief overview of mid-infrared science and future ground- and space-based facilities at mid-infrared and submillimeter wavelengths is given.
Rationale for the Joint Discussion
Authors: Conti Peter S. , Churchwell Edwin B.
Published: March 2016

This Joint Discussion (JD) will consider the birth processes of massive stars. While similar phenomena (e.g., accretion discs, outflows, etc.) are found in low mass star formation, additional physics must be considered given the ionization of the interstellar environment by Lyman continuum photons, stellar winds from the hot star(s), and their deeper gravitational potentials. This JD will bring together experts from several disparate astronomical communities: stellar astrophysics, interstellar medium, radio astronomy, and stellar dynamics. The concept is to contrast observations of very young stars and star formation regions over various wavelengths with theoretical expectations.
Studies of Compact HII Regions with ISO
Authors: Cox Pierre
Published: March 2016

We summarize results of a study of combined ISO SWS-LWS grating spectra of compact HII regions in our Galaxy.
The Supernebula and Protoglobular Cluster in NGC 5253
Authors: Turner Jean L.
Published: March 2016

A compact and bright radio and infrared source within the starburst center of the dwarf galaxy NGC 5253 appears to be an extremely large compact HII region. The high density (ne ~ few xlO4 cm-3) and size (∼1-2 pc) of the nebula require the ionization equivalent of at least 4000 O7 stars. We suggest that this optically obscured nebula is a forming super star cluster, or protoglobular cluster, with an age of a few hundred thousand years.
Definitions, Summary, and Some Issues
Authors: Conti Peter S.
Published: March 2016

This Joint Discussion has been titled Massive Star Birth. Perhaps it is appropriate here to define what we mean by a massive star. The very word massive suggests we consider a minimum mass M below which one would speak of low (or intermediate) mass evolution, and above which is the realm of massive stars. It is natural to take this mass limit as that in which a (single) star will end its life as a supernova: 8M⊙. This corresponds to a (minimum) luminosity L of a few × 103L⊙, a (minimum) Teff of 20000 K, and a ZAMS spectral type of about B1.5V. Note that this mass division refers to the final evolution of a star, and might well have nothing to do with difference in physical processes between massive and low mass star birth. For example, the minimum Teff for a star to produce an UCHII region, a readily observable quantity, corresponds to a Teff closer to 30000 K and a mass of 15M⊙.
The Exploration of the Transneptunian Population
Authors: Marsden Brian G.
Published: March 2016

The recognition of the extensive population of bodies in the outer Solar System has been arguably the most significant discovery about the Solar System from groundbased observations during the twentieth century. Our understanding of the transneptunian population is still quite flawed in its details, although a plausible picture has been emerging.
Regarding the Criteria for Planethood and Proposed Planetary Classification Schemes
Authors: Stern S. Alan , Levison Harold F.
Published: March 2016

We examine the question of planetary classification, making recommendations both for the criteria by which planethood should be evaluated, as well as for more detailed physical and dynamical subtype classification schemes.
Evolution of the Kuiper Belt during the Accretion of the Outer Planets
Authors: Brunini A. , Melita M.D.
Published: March 2016

A set of self-consistent simulations of the formation of Uranus and Neptune are performed to study the evolution of the native KBOs in the process. Our main goal is to have a deeper understanding of the impact of the formation of the outer planets on the present orbital structure of the trans-neptunian region. We aim to understand if resonance capture driven by the outward migration of Neptune can actually occur and its interplay with the invasion of massive planetesimals expelled from the Uranus-Neptune region as a byproduct of their formation. Also the putative present existence in the Oort reservoir of a population of objects originated in the Kuiper belt is analyzed.
Collisional Evolution of the Edgeworth-Kuiper Belt: Implications for the Origin and Evolution of Small Body Populations
Authors: Davis Donald R. , Farinella Paolo
Published: March 2016

Collisions have been a major process that shaped the Kuiper Belt that we see today. Collisional grinding likely played a significant role in removing mass from the trans-neptunian region and collisions are a mechanism for injecting fragments into resonances to start their journey to become short period comets. The Kuiper Belt preserves the accretional size distribution in bodies ≳ 100 km while the size distribution of smaller bodies is the result of collisional evolution. Observational confirmation of the transition size between these different regimes will constrain our understanding of the origin and evolution of the Kuiper Belt.
Horizontal Branch Models as a Test of Mixing on the RGB
Authors: Sweigart Allen V.
Published: March 2016

We discuss the impact of mixing and rotation along the red-giant branch (RGB) on the properties of horizontal-branch (HB) stars with emphasis on two problems: the nature of the unexpected blue HB population in the metal-rich globular clusters (GCs) NGC 6388 and NGC 6441 and the cause of the low gravities in the blue HB stars. New stellar models indicate that the sloped HBs in NGC 6388 and NGC 6441 might arise from a spread in metallicity, implying that these GCs may be metal-rich analogues of ω Cen. The low gravity problem can be largely explained by the radiative levitation of Fe in the atmospheres of the blue HB stars. We show that the onset of radiative levitation and the drop in HB rotation velocities at Teff ≈ 11,000 K coincide with the disappearance of surface convection. The low rotation velocities of the hotter HB stars may be due to the spin down of the surface layers by a weak stellar wind induced by the radiative levitation of Fe. We conclude that the impact of mixing and rotation on the HB remains to be clearly established.
Solar Eruptions - the Effects on the Earth’s Environment
Authors: Brekke P.
Published: March 2016

The response of our space environment to the constantly changing Sun is known as ”Space Weather”. The Solar and Heliospheric Observatory (SOHO) has obtained significant new information about coronal mass ejections (CMEs), the source of the most severe disturbances in the Earth’s environment. Most of the time space weather is of little concern in our everyday lives. However, when the space environment is disturbed by the variable outputs of the Sun, technologies that we depend on both in orbit and on the ground can be affected. The increasing deployment of radiation-, current-, and field-sensitive technological systems over the last few decades and the increasing presence of complex systems in space combine to make society more vulnerable to solar-terrestrial disturbances. Thus, our society is much more sensitive to space weather activity today compared to the last solar maximum. By observing the Sun 24 hours per day, SOHO has proved to be an important “space weather watchdog”. The importance of real-time monitoring of the Sun will be pointed out and a number of enterprises affected by space weather will be discussed.
Mechanism of Coronal Mass Ejections Triggered by Emerging Flux
Authors: Chen P.F. , Fang C. , Shibata K.
Published: March 2016

The origin of coronal mass ejections (CMEs) is an interesting, while still mysterious, subject in solar physics. As well, the relationship between CMEs and solar flares is poorly understood. This paper attempts to provide answers to these questions on the base of the flux rope model, and put forward a trigger mechanism for CMEs. The work is motivated by an interesting discovery of the relation between reconnection-favored emerging flux and CMEs (Feynman and Martin 1995), i.e., such emerging flux, either within the filament channel or on the outer edge of the channel, can trigger CMEs.

In the consideration of Aly’s constraint, a detached flux rope model was proposed for the pre-CME configuration. A quadrupolar magnetic field with a flux rope is introduced as the initial magnetic configuration in current research. Since our trigger mechanism is magnetic in nature, gravity is omitted. Emerging flux is simulated by changing the local magnetic flux at the bottom boundary.
Oxygen Abundances Derived from UV OH and O I IR Lines in Very Metal-Poor Stars
Authors: López Ramón J. García , Israelian Garik , Rebolo Rafael , Bonifacio Piercarlo , Molaro Paolo , Basri Gibor , Shchukina Natalya
Published: March 2016

Oxygen abundances have been derived in a sample of very metal-poor stars using the O I triplet at λλ 7771-5 Å and OH lines in the near UV. A detailed NLTE analysis of iron lines has been carried out for one of the observed stars, BD +23° 3130, providing consistent values of effective temperature and surface gravity that are in very good agreement with independent estimates from the infrared flux method and Hipparcos parallaxes, respectively. These parameters, especially the higher gravity obtained with respect to previous analyses, reduce the discrepancies claimed between the oxygen abundances determined from OH, O I triplet and [O I] λ 6300 Å lines, and give consistent abundances to within 0.16 dex for BD +23° 3130 ([Fe/H]NLTE = −2.43). The oxygen abundances derived for this new sample confirm previous findings for a progressive linear increase in the oxygen-to-iron ratio with a slope −0.33 ± 0.02 (including NLTE corrections to the iron abundances for all the stars considered) from solar metallicity to [Fe/H]∼ −3, and [O/Fe] values as high as ∼ 1.1 for stars with [Fe/H]≾ −2.5. These results can be interpreted as evidence for oxygen overproduction in the very early epoch of the formation of the Galactic halo, possibly associated with supernova events with very massive progenitor stars.
Lithium-Beryllium-Boron and Oxygen in the Early Galaxy
Authors: Vangioni-Flam Elisabeth , Cassé Michel
Published: March 2016

Oxygen is a much better evolutionary index than iron to follow the history of Lithium-Beryllium-Boron (LiBeB) since it is the main producer of these light elements at least in the early Galaxy. The O-Fe relation is crucial to the determination of the exact physical process responsible for the LiBeB production. Calculated nucleosynthetic yields of massive stars, estimates of the energy cost of Be production, and above all recent observations reported in this meeting seem to favor a mechanism in which fast nuclei enriched in He, C and O arising from supernovae are accelerated in superbubbles and fragment on H and He in the interstellar medium.
The Dawn of Galaxies: Deep MAMBO Imaging Surveys
Authors: Bertoldi F. , Menten K.M. , Kreysa E. , Carilli C.L. , Owen F.
Published: March 2016

We discuss results from sensitive, wide-field imaging of the millimeter extragalactic background using the Max-Planck Millimeter Bolometer array (MAMBO) at the IRAM 30 m telescope.
Chandra Observations of Clusters of Galaxies
Authors: Forman W. , Donnelly H. , Markevitch M. , Kraft R. , Murray S. , Vikhlinin A. , Churazov E. , David L. , Jones C.
Published: March 2016

We discuss two themes from Chandra cluster observations. First, we describe the interaction of buoyant, radio emitting plasma bubbles with the hot intracluster gas. Second we summarize the Chandra observations of “cold” fronts (sharp discontinuities in gas density and temperature) separating cool, denser gas clouds from the hotter intracluster medium.
First Results on Clusters Observed by XMM/EPIC
Authors: Arnaud M. , Aghanim N. , Belsole E. , Gastaud R. , Majerowicz S. , Neumann D.M. , Sauvageot J.L.
Published: March 2016

First spatially resolved spectroscopic observations of the Virgo and Coma clusters made with XMM during the PV phase are presented. The implication for the dynamical state of these clusters are briefly discussed.
Simulations of Merging Clusters of Galaxies
Authors: Schindler Sabine
Published: March 2016

Numerical simulations of cluster mergers reveal many characteristics of the merging process: shock structure and strength, observational signatures of the dynamical state, effects on the mass determination, turbulence and the evolution of the X-ray luminosity and the magnetic field. In this article I review the results obtained from various simulations over the last years.
Base de Données d’Images Planétaires (BDIP): One Century of Planetary Images: 1870-1977
Authors: Drossart Pierre , Roques Françoise , Birnbaum Cyril , Boyer René , Neyvoz Eliane
Published: March 2016

The digitization of the planetary database of IAU has been performed, to give access to historical data in digital format. The database is constituted from the planetary photograph center collections, which was organized in 1961 at the request of the IAU (IAU conferences; Last reference: 1979, IAU Trans., XVIIA, 109). From this collection, 8473 images have been digitalized and are now accessible on line in a compressed format at the Web address: http://bdipwww.obspm.fr. The catalog information, including date and time of observations, and geometric configuration is completed for Jupiter and Saturn. The database contains plates recorded between 1870 and 1977:

Jupiter: 2715 images

Saturn: 357 images

Mars: 4661 images

Venus: 835 images

Mercury: 105 images
Extragalactic Magnetic Fields in the Extragalactic Universe and Scenarios Since Recombination for their Origin
Authors: Kronberg Philipp P.
Published: March 2016

I briefly review recent observations, some related physics and modelling, and future possibilities relating to our knowledge of the strength, structure and evolution of extragalactic magnetic fields.
The Origin of Magnetic Fields in Elliptical Galaxies
Authors: Shukurov Anvar
Published: March 2016

We argue that interstellar gas in elliptical galaxies can be turbulent, with turbulent scale and velocity of 400 pc and 20 km s−1 respectively. An upper limit on turbulent velocity, ≃ 50 km s−1, follows from the requirement that the turbulence dissipation rate does not exceed the X-ray gas luminosity. The turbulence can generate random magnetic fields of 0.3 μG strength at the above scale via fluctuation dynamo action. The resulting Faraday rotation is random, with a typical value of 5-30 rad m−2, consistent with observational evidence available.
Overview of Interferometer-Type Gravitational Wave Detectors
Authors: McClelland David E
Published: March 2016

Within the next decade giant laser interferometers should detect gravitational waves. Here we present an overview of these instruments including both ground and spaced based antennae.
Experimental Progress in the Direct Detection of Dark Matter
Authors: Smith Nigel J.T.
Published: March 2016

Several experimental approaches are being utilised for the direct detection of the hypothetical weakly interacting massive particle which may constitute the majority of the non-luminous component of the Galaxy. These experimental techniques exploit the coherent recoil of target nuclei during an interaction and include thermal, ionisation, scintillation and tracking detectors. The challenges associated with this detection, the techniques employed and the current status of these searches are reviewed.
Magnetic Helicity Conservation
Authors: Berger Mitchell A.
Published: March 2016

Magnetic Helicity measures basic structural properties of magnetic fields such as twist, shear, linking, writhe, and handedness. It is conserved in ideal MHD and approximately conserved during reconnection. The minimum energy state of a field with a given magnetic helicity is a linear force free field. Helicity plays an important role in MHD turbulence and dynamo theory, and provides a valuable observational tool in solar and space physics. Helicity conservation can be tracked from the solar dynamo to active regions to coronal mass ejections to magnetic clouds in interplanetary space.
Technique for Inferring Magnetic Helicity of Active Regions
Authors: Chae Jongchul , Moon Yong-Jae
Published: March 2016

We provide the rationale for the wide applicability of the LCT method for inferring the magnetic helicity of an active region, with an illustrative application made to NOAA 10365. We also report that the determined rate of helicity change is not much sensitive to the free parameters of the LCT method. The application of the method to active regions by several investigators has produced results suggesting that the magnetic helicity of a major active region with flux 1022 Mx may be usually of the order of 1043 Mx2 or less, being twisted at most 0.1 turns as a whole.
Helicity Pattern of CME Source Active Regions
Authors: Wang Jingxiu , Zhou Guiping , Zhang Jun
Published: March 2016

Coronal mass ejections are thought to originate from the over accumulation of magnetic helicity (Rust & Kumar, 1994). While recent studies revealed the incompetence of CME associated active regions in creating enough helicity for CMEs (Nindos, Zhang, & Zhang, 2003 and references therein), we have tried to seek, on the other hand, if particular helicity patterns are retained by CME-associated active regions.
Helicity of Magnetic Clouds and Their Associated Active Regions
Authors: Leamon Robert J. , Canfield Richard C. , Jones Sarah L. , Lambkin Keith , Lundberg Brian J. , Pevtsov Alexei A.
Published: March 2016

Magnetic clouds are associated with many Coronal Mass Ejections. Many CMEs involve active regions. In this work we focus on the relationship between twelve magnetic clouds and their associated active regions. We use a cylindrically symmetric constant-a force-free model to derive field line twist, total current, and total magnetic flux from in situ observations of magnetic clouds. We compare these properties with those of the associated solar active regions, which we infer from solar vector magnetograms.

Our comparison of fluxes and currents reveals: (1) the total (unsigned) flux ratios ФMC/ФAR tend to be of order unity; (2) the total flux ratios tend to be orders of magnitude larger than the total (unsigned) current ratios IMC/IAR; and (3) there is a statistically significant proportionality between them. Our key findings in comparing total twists αL, where L is the axial dimension of the system, are: (1) the values of (αL)MC are typically an order of magnitude greater than those of (αL)AR; and (2) there is no systematic sign or amplitude relationship between them. These findings compel us to believe that magnetic clouds associated with active region eruptions are formed by magnetic reconnection between these regions and their larger-scale surroundings, rather than pre-existing structures in the corona or chromosphere.
Formation of Star Clusters in the LMC and SMC
Authors: Bekki Kenji , Couch Warrick J. , Forbes Duncan A. , Beasley M. A.
Published: March 2016

We demonstrate that single and binary star clusters can be formed during cloud-cloud collisions triggered by the tidal interaction between the Large and Small Magellanic clouds. We run two different sets of self-consistent numerical simulations which show that compact, bound star clusters can be formed within the centers of two colliding clouds due to strong gaseous shocks, compression, and dissipation, providing the clouds have moderately large relative velocities (10 — 60 km s-1). The impact parameter determines whether the two colliding clouds become a single or a binary cluster. The star formation efficiency in the colliding clouds is dependent upon the initial ratio of the relative velocity of the clouds to the sound speed of the gas. Based on these results, we discuss the observed larger fraction of binary clusters, and star clusters with high ellipticity, in the Magellanic clouds.
SUBARU/FOCAS Globular Clusters Survey around M82
Authors: Saito Yoshihiko , Iye Masanori , Kashikawa Nobunari , Kawabata Koji S. , Yoshida Michitoshi , Ohyama Youichi , Sasaki Toshiyuki , Takata Tadafumi , Kosugi George , Aoki Kentaro
Published: March 2016

Recently, a number of possible young globular clusters (GCs) have been found in some merging/interacting galaxies or starburst galaxies. On the other hand, it is well known that GCs are numerous in giant elliptical galaxies many of which are thought to be formed via major merger of galaxies. These facts lead us to a thought that the formation process of GCs could accompany galaxy – galaxy interaction followed by starburst. The archetypical starburst galaxy M82 is an ideal target to study the relation between galaxy interaction, starburst, and GC formation.
Semi-detached Binaries as Probes of the Local Group
Authors: Wilson Robert E.
Published: March 2016

The SMC I band light curves of the OGLE project show a curious absence of familiar Algols. Comparitive statistical work for SMC and Milky Way Algols might uncover an evolutionary explanation, presumably connected with chemical composition, or may point to observational selection or even merely perception. As background, LMC and SMC abundances of nitrogen, oxygen, and neon are lower than in our Galaxy by respective factors of about 2.5 and 6, raising the issue of metallicity effects on semi-detached (SD) statistics – specifically on SD light curves and numbers of SDs. Lobe overflow is a triggered process, with both system age and structural configuration at triggering dependent on composition.
Chemistry in Protoplanetary Disks
Authors: Aikawa Yuri
Published: March 2016

Molecular evolution is calculated in migrating fluid parcels in a protoplanetary disk considering gas-phase and grain-surface reactions. Radial distribution of molecules is obtained, which depends on ionization rate, temperature and/or desorption rate in the disk. If the temperature is high enough (> 20 K) or non-thermal desorption is efficient enough to sublimate dominant species such as CO in the comet forming regions, the desorbed species are transformed to less volatile species and again incorporated into ice mantles. Chemistry in these outer disks is similar to that in molecular clouds; it produces both oxidized and reduced species with a high D/H ratio.
IAU XXV JD17: Atomic Data For X-Ray Astronomy
Authors: Pradhan Anil K. , Nahar Sultana N. , Smith Peter L.
Published: March 2016

The Joint Discussion on Atomic Data For X-ray Astronomy addressed all aspects of X-ray astronomy: (I) New Observations, (II) Atomic Theory, (III) Laboratory Measurements (IV) Numerical Simulations, and (V) Databases. There were 22 invited presentations and approximately 40 contributed papers. Following papers are brief summaries of the proceedings. A detailed description of the aims and contents of JD17 are given at: www.astronomy.ohio-state.edu/~pradhan/Iau/iau.html. The SOC consisted of: N. Brickhouse (USA), H. Hasan (USA), J. Houck (USA), A. Fabian (UK), J. Kaastra (Netherlands), F. Keenan (UK), S. Kahn (USA), T. Kallman (USA), H. Netzer (Israel), A.K. Pradhan (USA, Chair), P.L. Smith (USA), K. Yamashita (Japan).
Probing X-ray Emitting Plasma with High Resolution Chandra and XMM-Newton Spectra
Authors: Lee Julia C.
Published: March 2016

Highlights of interesting astrophysical discoveries are reviewed in the context of high resolution X-ray spectroscopy made possible with Chandra and XMM-Newton, and its relevance to atomic physics calculations and measurements is discussed. These spectra have shown that the overlap between astrophysics and atomic physics is stronger than ever, as discoveries of new X-ray lines and edge structure is matching the need for increasingly detailed theoretical calculations and experimental measurements of atomic data.
New Results in Laboratory X-ray Astrophysics
Authors: Beiersdorfer P. , Chen H. , Boyce K. R. , Brown G. V. , Kelley R. L. , Porter F. S. , Stahle C. K. , Lepson J. K. , Jernigan J. G. , Wargelin B. J. , Kahn S. M.
Published: March 2016

A multi-faceted, multi-institutional laboratory astrophysics program is carried out at the Livermore electron beam ion trap facility, which is a mature spectroscopic source with unsurpassed controls and capabilities, and an unparalleled assortment of spectroscopic equipment, including a full complement of grating and crystal spectrometers and a 6x6 micro-calorimeter array. Recent results range from the calibration of x-ray diagnostics, including the Fe XVII and Fe XXV emission lines, extensive lists of L-shell ions, the first laboratory simulation and fit of a cometary x-ray emission spectrum, and the discovery of new spectral diagnostics for measuring magnetic field strengths.
Future NASA Programs and Funding Support
Authors: Hasan Hashima
Published: March 2016

The future of Astronomy and Physics programs in the Office of Space Science is presented in the context of the overall NASA Strategic Plan. The highlights of the new road maps for the Origins and Structure and Evolution of the Universe science themes are given. A new initiative, Beyond Einstein, is discussed. New opportunities for technology development, building small missions, and conducting basic research and analysis to support NASA’s strategic goals are outlined. The status of NASA’s archives for data from its astronomy missions is presented.
High-Resolution Infrared Far-IR Spectroscopy from SOFIA, 2005-2025
Authors: Davidson J. A. , Erickson E. F.
Published: March 2016

NASA and the DLR are developing SOFIA, the Stratospheric Observatory for Infrared Astronomy: a 2.5 m telescope in a Boeing 747SP aircraft. By flying in the lower stratosphere, SOFIA will allow astronomical measurements covering the wavelength range from 0.3 μm to 1.6 mm, with an emphasis on the spectral regions inaccessible from the ground, particularly the 6-8 μm and 30-300 μm regions. SOFIA will see “first light” in 2004; the science program will start in 2005. An operational lifetime of 20 years is planned.

SOFIA will support a diverse and evolving complement of state-of-theart science instruments. Its spectrometers will have resolutions ranging from ~ 108 down to ~ 100, as needed to measure absorption and emission from astrophysically significant atoms, ions, molecules, aerosols, and solids. This paper describes the spectrometers being developed to fly on SOFIA soon after first light, and summarizes some of the high-spectral resolution investigations expected.
Hot Hydrogen in the Jovian Corona
Authors: Emerich C. , Ben Jaffel L. , Clarke J. T. , Ballester G.
Published: March 2016

The asymmetry observed in the H-Lyα profiles measured near the Jovian equatorial limbs by the STIS/HST spectrograph is interpreted as due to H atoms propagating in the upper Jovian atmosphere with velocities ~ 80 km/s relative to Jupiter’s rotation. A qualitative scenario is suggested to correlate these energetic H atoms to energetic neutral particles recently detected by Cassini at higher altitudes.
Working Group on Designations and Special Session 3
Authors: Dickel Helene , Schmitz Marion
Published: March 2016

The WGD is a part of Commission 5 – Documentation and Astronomical Data. There is a president, vice-president, and over a dozen members world-wide.

One duty of the WG is to maintain and update a web-site which contains the IAU Recommendations for Nomenclature. These recommendations include suggestions for creating new names for objects and examples of improper nomenclature.
Nomenclature for Multiple Systems Containing Close Binaries
Authors: Scarfe C.D.
Published: March 2016

I would like to discuss the difficulty of developing and maintaining a hierarchical designation scheme for components of multiple systems, when components are found by more than one method. Such a sequence of discoveries can easily lead to conflict between the initial nomenclature, which gets established in the literature, and that based on a scheme that is in broader use, or is more physically representative, or both. I will describe as an example a hypothetical complex system whose hierarchical description depends on the sequence in which discoveries are made, and whose designation in discovery order is ambiguous. In the end I urge flexibility in designations.
Distance/Internet Astronomy Education
Authors: McKinnon David H.
Published: March 2016

This paper briefly reports two major programs being operated by Charles Sturt University, Bathurst: the Cosmology Distinction Course for gifted and talented senior high school students and the CSU Remote Telescope Project for upper-elementary and lower secondary school students.
Fostering Science Education in the Developing Countries
Authors: White James C.
Published: March 2016

Considerable attention is paid to how we teach science and to how our students learn it. Even though similar questions are asked by scientists and science teachers in all countries, one finds that resources available for science education in developing countries are often scarce.