bluuebunny/crossref_metadata_2025 huggingface dataset:
The 10 GHz Log N - Log S Curve Obtained at NRO
Authors: Aizu Ko , Inoue Makoto , Tabara Hiroto , Kato Tatsuji
Published: July 2016

Using 45-m radio-telescope at NRO, we obtained log N - log S curves at 10 GHz for flat- and steep-spectrum sources separately. A simple model-fitting of evolution is given.
Ultradeep Optical Identifications and Spectroscopy of Faint Radio Sources
Authors: Windhorst Rogier A. , Dressler Alan , Koo David C.
Published: July 2016

During the last two years we have completed an extensive project of direct CCD imaging with the Palomar 200 inch Four-shooter on several milliJansky and microJansky radio samples, now totaling 200 sources. The purpose is to study the nature and redshift distribution of the radio galaxies that cause the upturn in the milliJansky source counts (WMOKK) and to search for candidates of primeval radio galaxies.
The Distribution of X-Ray Emitting Quasars in Space
Authors: Setti G.
Published: July 2016

This review is mainly concerned with the discussion of the statistical properties of X-ray and optically selected samples of quasars and Sy 1 nuclei and their intercomparison. The inconsistencies which have been found are clearly exemplified by the discrepancy between the observed and the predicted X-ray source counts. It is shown that a satisfactory understanding of these problems has not yet been reached. The last section deals with the long debated contribution of AGNs to the extragalactic X-ray background (XRB), which is still uncertain within a factor of 2, although a lower bound of 30% at the (now convenient) energy of 2 keV can be set.
The Infrared Spectra of Quasars - A Luminosity Dependence
Authors: Wills Beverley J.
Published: July 2016

The IR-optical-UV continua of quasars are often represented by two components: (i) a flat spectrum component dominating in the optical-UV (the “Big Bump”) and sometimes attributed to thermal radiation from an accretion disk with temperatures of about 20000 to 40000 K - we will call it the “disk” component - and (ii) a near IR component characterized by a steep rise, α ∼ 1 for λ > 1 μm, often thought to be a synchrotron spectrum - an extrapolation of the cm or mm wavelength radio spectrum - although some have preferred an explanation in terms of thermal re-radiation of the ionizing continuum by hot dust (e.g., Hyland and Allen 1982, Neugebauer et al. 1979).
The Application of the Study of Galaxies Associated With Quasars to Observational Cosmology
Authors: Yee H.K.C.
Published: July 2016

CCD direct imaging of fields around quasars is used as a method for locating galaxy clusters and groups associated with quasars. Average galaxy counts in the sky obtained from control fields are used to correct for background galaxies in the quasar fields. This correction allows one to derive the luminosity function (LF) of the associated galaxies at the redshifts of the quasars. It is demonstrated that using the derived LF and average galaxy count data, self-consistent models of the evolution of the LF and galaxy counts can be obtained. Current data are best fitted, with a large uncertainty, by a qo between 0.0 and 0.5 and an evolution in M* of −0.9±0.5 mag. It is found that the average environment of radio-loud quasars at z∼0.6 is about three times richer in galaxies than that of quasars at z∼0.4.
Dark Matter
Authors: Sancisi R. , van Albada T.S.
Published: July 2016

The observational evidence for unseen matter is briefly reviewed for objects ranging from small to very large scales. The existence of large mass discrepancies is clearly recognized in individual spiral galaxies and in rich clusters of galaxies. For other systems - dwarfs, ellipticals, binaries and groups - the results are more uncertain and still rather controversial. The data on spirals indicate values of the cosmological density parameter Ω around 0.02, those on clusters Ω ≃ 0.2. The spatial distribution of this dark matter is still largely unknown: while on the galaxy scale it must be located mainly in the outer parts of the stellar system, in clusters it is unclear whether it follows the distribution of the visible galaxies or not.
Multiwavelength Properties of Narrow-line Seyfert 1's: Studying One Extreme of the AGN Primary Eigenvector
Authors: Hirst Paul , Law-Green Duncan , Ward Martin
Published: July 2016

Narrow Line Seyfert 1 galaxies (NLS1s) are an important subclass of radio quiet AGN having extreme optical and X-ray spectroscopic properties. Their relationship to other types of Seyferts remains unclear. NLS1s exhibit many characteristics of Seyfert 1 AGN, but their optical spectra show narrow permitted lines, and some high ionization species. This may result from us viewing them close to ‘pole-on' orientation with respect to an inner torus geometry. We present comparisons of the radio and X-ray properties of NLS1s with those of the 12μm and CfA Seyfert samples.
Global Oscillations of Masing Disks in Megamasers
Authors: T. Okazaki Atsuo
Published: July 2016

We study the characteristics of global oscillation modes of masing disks in megamasers and the effect of the modes on the disk kinematics. We find that the eccentric mode is responsible for the observed sub-Keplerian velocity distribution of the maser source of NGC 1068, whereas in the masing disk of NGC 4258 the warping mode is dominant so that the angular rotation velocity remains near Keplerian.
Quasars
Authors: S. Osmer Patrick
Published: July 2016

I review recent results for quasars and discuss how they are related to activity in galaxies. Topics included are studies of quasar host galaxies with HST; searches for quasars in the Hubble Deep Field; evolution of the quasar luminosity function; news highlights from astro-ph; and current observational research problems and their relation to theoretical work.
The Evolution and Luminosity Function of Quasars
Authors: Petrosian Vahé
Published: July 2016

I report results from analysis of data from several quasar samples (Durham/AAT, LBQS, HBQS and EQS) on the density and the luminosity evolution of quasars. We have used new statistical methods whereby we combine these different samples with varying selection criteria and multiple truncations. With these methods the luminosity evolution can be found through an investigation of the correlation of the bivariate distribution of luminosities and redshifts. Of the two most commonly used models for luminosity evolution, L = ekt(z) and L = (1 + z)k', we find that the second form, with k' = 2.58 (one σ range [2.14,2.91]), gives a better description of the data at all luminosities. Using this form of luminosity evolution we determine a global luminosity function and the evolution of the co-moving density for the two classes of cosmological models. We find a gradual increase of the co-moving density up to z ˜ 2, at which point the density peaks and begins to decrease rapidly. This is in agreement with results from high redshift surveys and in disagreement with the pure luminosity evolution (i.e. constant co-moving density) model. We find that the local luminosity function exhibits the usual double power law behavior. The luminosity density is found to increase rapidly at low redshift and to reach a peak at around z ≍ 2. This result is compared with those from high redshift surveys and with the evolution of the star formation rate.
Markarian and Seyfert Galaxies
Authors: Khachikian E. Ye.
Published: July 2016

Since this symposium is devoted to the 90th anniversary of Prof. Ambartsumian's birthday I would like to touch briefly upon some historical aspects of V. Ambartsumian's ideas on activity of nuclei of galaxies.
Identification of Faint Markarian Galaxies with IRAS Sources
Authors: Ayvazyan V. T.
Published: July 2016

Identifications of IRAS sources with faint Markarian galaxies on the base of the Second Byurakan Survey were made. It is shown that about 30% of SBS galaxies are also IRAS sources. The list of newly identified objects is presented.
Monitoring of 1-22 GHz Instantaneous Spectra of 550 Compact Extragalactic Objects in 1997-1998
Authors: Kovalev Y.Y. , Nizhelsky N.A. , Kovalev Yu.A. , Sidorenkov V.N. , Mingaliev M.G. , Bogdantsov A.V.
Published: July 2016

First results of six frequency observations at five epochs in March, 1997, –- April, 1998, and a statistical analysis are presented.
Quantized Redshifts - New Physics or Old Muddle?
Authors: Napier W.M.
Published: July 2016

The HI redshift distribution of nearby spiral galaxies has been studied to test long-running but generally ignored claims that extragalactic redshifts are periodic or ‘quantized’. The existence of the phenomenon is confirmed at an extremely high confidence level, the quantization appearing in the galactocentric frame of reference. It is proposed that the energy density of the vacuum is a local, oscillating quantity associated with large masses such as spiral galaxies. A variety of ‘anomalies’ should then be detectable in massive galaxies, associated with their redshifts, their ambient gravitational lensing and their dynamics.
Diffusion Mechanism of Radiation of a Charged Particle on the Randomly Spaced Dust Grains in the X-Rays
Authors: Gevorkian Zh. S. , Hambaryan V. V. , Akopian A. A.
Published: July 2016

The theory of diffusion radiation of a charged particle on the fluctuations of the dielectric constant developed by Gevorkian can be explained as follows:

A charge moving in a medium creates an electromagnetic field (pseudophoton) which is scattered on the fluctuations of the dielectric constant (here, dust particles) and converted into radiation. In the wavelength region (l « λ « L) (l is the mean free path of the photon in the medium, L is the characteristic size of the system) the main mechanism of the radiation is the diffusion of the pseudophoton (Gevorkian & Atayan 1990, Gevorkian 1992, Gevorkian 1993).
M87 Solves the Problem of AGN
Authors: Iskudarian S. G.
Published: July 2016

The example of M87 shows that AGN are the most powerful units of protogalactic matter, which has built the large scale Universe during parts of the first second of the Big Bang. For fulfilment of such a mission it had to possess properties of elementary particles.
Variable Sources in Active Galactic Nuclei
Authors: Hagen-Thorn V. A. , Marchenko S. G. , Yakovleva V. A. , Hagen-Thorn A. V.
Published: July 2016

The problem of the activity of extragalactic objects is one of the main problems of current astrophysics. There are many manifestations of activity but the photometric and polarimetric variability in IR, optical, UV and X-ray regions is probably one of the most important. The sources responsible for the variability are placed in the nearest neighbourhood of a central engine. Clarifying the nature of these sources might give a tool to the solution of the problem of nuclear activity in general.
Variability of the Broad Emission Hβ Profile in 3C390.3
Authors: Burenkov A.N. , Shapovalova A.I. , Vlasyuk V.V. , Bochkarev N.G.
Published: July 2016

The object 3C390.3 is a well known broad-line radio galaxy (z=0.056), whose very broad emission lines are variable in time (see Veilleux and Zheng 1991, and Dietrich at al. 1998 for references). It is known as the prototypical source of broad double-peaked Hβ and Hα emission lines. In this paper we present the preliminary results of spectral observations of 3C390.3 in 1995–1998 on 6-m and 1-m telescopes of the Special Astrophysical Observatory of RAS.
The Role of Neutral Hydrogen in the Evolution of Sprial and Irregular Galaxies
Authors: Ambartsumian V.A. , Gyulbudaghian A.L.
Published: July 2016

The Hubble classification suggested for the spiral galaxies, Sa–Sb–Sc–Sm–Irr, was considered by many astronomers as an evolution succession. The version of transformation from early spirals to the late spirals and vice versa was considered. The existence of several parameters, monotonically increasing or decreasing along this succession, together with the parameters which do not depend on the structural type of the galaxies of this succession, is a confirmation of this succession to be a succession of stages of evolution. Let us consider in detail both types of parameters. About the full masses and luminosities of galaxies we can state, that except Irr and maybe Sm-galaxies there is not a clear expressed difference of mean values of these parameters for galaxies of different structural types. Irr galaxies are the systems with low masses and luminosities, but on the (M-L) diagram a part of them is obviously mixed with the late spirals. There is a strong change of the M/L ratio with changing of the structural type, though the early type galaxies on average apparently have the least values of that ratio. As monotonically changing parameters we can suggest the following three:
Recent Satellite Observations of X-ray Emission from AGN
Authors: Kunieda H.
Published: July 2016

Recent X-ray satellite observations provide plenty of spectral information with high resolution in a broad band. Major results from the spectral observations are related to the interaction of the power-law continuum flux with the ambient plasmas and accretion disks. The most prominent result is the broad iron-line feature from Seyfert I galaxies which is interpreted as the emission from the relativistic accretion disk. Doppler shift and boosting, as well as gravitational redshifts, are considerable at the distance of several Schwarzschild radii from the central black hole. Strong radiation from the central engine ionizes the ambient material of AGN. Edge structure found at around 0.8 keV is attributed to highly ionized oxygen of O VII and O VIII. Some iron emission lines from Seyfert II galaxies are emitted by highly photoionized plasmas. The study of fast temporal and spectral variability is the key approach to examine the emission mechanism and structure of the central vicinity of AGN. In 2000, two X-ray observatories (Chandra and XMM will be in orbit, and they will provide us with deeper insights of the physics around the black holes and of the physics of hot plasmas.
Neutron Stars in Supernova Remnants
Authors: Pacini F.
Published: July 2016

In the following, we shall briefly summarize some facts and ideas concerning the presence of neutron stars in supernova remnants. While sources similar to the Crab Nebula require the presence of a central energetic object, shell-type remnants such as Cas A are compatible with the presence of neutron stars releasing a weak relativistic wind.
Multiwavelength Diagnostics of Pulsar Plasmas
Authors: Romani R. W.
Published: July 2016

The phase-resolved broadband (optical to gamma-ray) spectral energy distributions of spin-powered pulsars contain important diagnostics of the emission zone plasma and its acceleration. I summarize some recent observations of young pulsars, describe models for the various spectral components, and argue that the next generation of telescopes and spacecraft will allow a true mapping of the e±plasma flow in the pulsar magnetosphere. Of course, spectral lines and breaks are more powerful tracers than the spectral energy distribution, and since we believe that synchrotron emission dominates in the near-IR to UV, features are expected that will allow even more detailed probes of the plasma physics. Most young pulsars are, however, quite faint, and new technology is needed to extract these diagnostics.
The Scaling of Solar Flare Hard X-ray Emission to Other Flaring Objects in the Universe
Authors: Martens P. C. H.
Published: July 2016

Fletcher & Martens have successfully modeled solar hard X-ray sources observed at the top and footpoints of flaring magnetic loops with a Fokker-Planck type particle transport code. I show here that there are invariances in the Fokker-Planck equations that make these results applicable to environments with vastly different physical parameters, such as hard X-ray flares in accretion disks in active galactic nuclei, and in RS CVn and ALGOL type binaries.
X/γ-rays from Active Galactic Nuclei
Authors: Svensson R.
Published: July 2016

Recent progress using RXTE and BeppoSAX to study the X/γ emission from radio-quiet active galactic nuclei, i.e., Seyfert galaxies, is reviewed. These satellites allow simultaneous broad-band spectra extending from 0.1–200 keV to be observed for the first time and allow the various spectral components to be determined with some certainty. In particular, the new observations support the unified model of Seyfert galaxies. Most importantly, it has been found that a large fraction of Seyfert 2 galaxies have Compton-thick tori surrounding their nuclei. Spectral transitions in Seyfert galaxies are discussed, as well as recent efforts trying to synthesize the cosmic X/γ-ray background. Finally, thermal Comptonization in these sources are discussed.
Population Synthesis of GRB Progenitors: Problems With Kicks
Authors: Fryer C. L.
Published: July 2016

Accretion disks around stellar-mass black holes are now thought to be the engines which power classical gamma-ray bursts (GRBs). These disks are formed almost exclusively in binaries, and to study the characteristics of the progenitors of these black-hole accretion disk (BHAD) GRBs, we must understand the uncertainties in binary population synthesis calculations. Kicks imparted onto nascent neutron stars and black holes are among the most misunderstood concepts of binary population synthesis. In this paper, we outline the current understanding (or lack of understanding) of these kicks and discuss their effect on BHAD GRBs and binary population synthesis as a whole.
Starquakes in Neutron Stars
Authors: Franco L. M. , Link B. , Epstein R. I.
Published: July 2016

The Crab and other pulsars suffer sudden and permanent increases in their spin-down rates in association with glitches, suggesting that the external torque on these objects grows in steps. Here, we describe how torque changes may arise from starquakes, occurring as the star spins down and its rigid crust becomes less oblate. We study the evolution of strain in the crust, the initiation of starquakes, the effects on the magnetic field geometry, and possible observable consequences for neutron star spin down. We find that the stellar crust begins breaking at the rotational equator, forming a fault inclined at an angle to the equator and directed toward the magnetic poles. The resulting asymmetric matter redistribution produces a misalignment of the angular momentum and spin axes. Subsequently, damped precession to a new rotational state increases the angle between rotation and magnetic axes. The change in this angle could increase the external torque, producing a permanent increase in the spin-down rate.
Internal Rotation of AB Doradus
Authors: Hiremath K. M.
Published: July 2016

Using Chandrasekhar's MHD equations, we solve for the steady part of the internal rotation of AB Doradus. We estimate the size of the convective envelope to be ~ 40% of the radius and the rotation velocity at the base to be not less than 1.42 × 10−4 rad/sec. This study also yields the steady part of the toroidal magnetic field which is distributed throughout the convective envelope. We present rotational and toroidal magnetic field profiles in the interior and conjecture on the time-dependent part of the magnetic field.
Particle Acceleration and Radiation in Magnetospheres of Collapsing Stars
Authors: Kryvdyk V.
Published: July 2016

Particle dynamics and nonthermal emission therefrom in the magnetospheres of collapsing stars with initial dipole magnetic fields and a certain initial energy distribution of charged particles (power-law, relativistic Maxwell, and Boltzmann distributions) are considered. The radiation fluxes are calculated for various collapsing stars with initial dipole magnetic fields and an initial power-law particle energy distribution in the magnetosphere. The effects can be observed by means of modern instruments.
Interaction of the SS433 Jet with the Interstellar Medium
Authors: O'Neill P. , Sood R. , Durouchoux P. , Safi-Harb S.
Published: July 2016

X-ray emission observed from the SS433/W50 system has been interpreted as resulting from the interaction of the binary jets with the surrounding medium. We have been carrying out millimetre wavelength measurements of this system. We find no evidence for the association of a molecular cloud with the eastern jet, but we do find evidence for a strong association with the western jet.
NLTE Model Atmospheres for Extremely Hot Compact Stars
Authors: Rauch T. , Deetjen J. L. , Dreizler S. , Werner K.
Published: July 2016

Present observational techniques provide stellar spectra with high resolution at a high signal-to-noise ratio over the complete wavelength range—from the far infrared to X-rays.

The effects of Non-“Local Thermal Equilibrium” (NLTE) are particularly important for hot stars, hence the use of reliable NLTE stellar model atmosphere fluxes is required for an adequate spectral analysis.

State-of-the-art NLTE model atmospheres include metal-line blanketing of millions of lines of all elements from hydrogen up to the iron-group elements, and thus permit precise analyses of extremely hot compact stars, e.g., central stars of planetary nebulae, PG 1159 stars, white dwarfs, and neutron stars. Their careful spectroscopic study is of great interest in several branches of modern astrophysics, e.g., stellar and galactic evolution, and interstellar matter.
Self-organized Criticality with Data from MCG-6-30-15?
Authors: Sivron R. , Goralski E. , LeRoux A. , Tsuruta S. , Kunieda H.
Published: July 2016

We explain why compact sources are nonlinear and investigate the nonlinearity of MCG-6-30-15. We argue that the central engine of this Seyfert nucleus is compact and show that it exhibits a specific nonlinear behavior similar to that of a system in a critically self-organized state.
Astrophysics in the New Millennium
Authors: Canizares C. R.
Published: July 2016

I am going to use this opportunity to make some very general remarks. I believe we are about to enter an era that is very different from those we have experienced before, and is probably closest to what those of us who have been around long enough experienced in the 1970s. That was a time of explosive expansion in space astronomy and astrophysics. The intervening two decades have seen major advances in many specific areas, but, since the 1970s period, progress has been more episodic, triggered by the occasional appearance of some new observational tool, new computational tool, or theoretical insight.
Light Pollution: Changing the Situation to Everyone's Advantage
Authors: Crawford David L.
Published: July 2016

There is no question of the need for outdoor lighting to improve the effectiveness of our night-time environment. However, too much of the lighting installed to try to meet this need actually compromises the purpose, and it too often adversely affects the night-time environment, including our view of the stars and of the Universe above us. This urban sky glow severe impacts on all of astronomy, amateur and professional, as well as those of the public who enjoy and profit by the beauty offered by a prime dark sky. In the present paper, I review the issues involved and suggest guidelines to minimize these negative aspects of poor night-time lighting. With good outdoor lighting we all win.
Sky Glow Measurements in the Netherlands
Authors: Schreuder Duco A.
Published: July 2016

Sky glow was measured in the Netherlands in 1992 and in 1997. The 1992 measurements were photographic surveys, assessed in the Netherlands and in Japan, whereas the 1997 measurements were limit-star assessments. In all cases, the number of measurements was very small. The three sets of data are compared. The sky glow differs considerably over the country and during the night; there are no systematic differences between the results for different epochs and assessment methods. For measurements that allow conclusions that can be used in national policy making, the samples must be very much larger.
Light Pollution in Quebec
Authors: Dutil Yvan
Published: July 2016

As in any developed country, light pollution is a serious problem in Quebec. However, a specific cultural and economical situation forces us to use new tactics when it is time to discuss this problem. As an example, using energy loss as an argument against light pollution is very inefficient since the electricity is cheap (US$0.04/kWh) and clean (hydroelectricity). On the other hand, using the negative ecological impacts of light pollution appears to be the most effective way to create awareness in the population.
Protection of Millimetre-Wave Astronomy
Authors: Ohishi Masatoshi
Published: July 2016

Development of radio technologies will lead to a serious conflict between millimetre-wave astronomy and telecommunication services. I describe characteristics of millimetre-wave astronomy and technical aspects related to radio astronomical observations. Three examples of possible interference to millimetre-wave astronomy are described. It is very important to advertise what millimetre-wave astronomy contributes to human culture and to get support from the non-astronomical community to keep the radio windows open and clean.
Radio Interference Monitoring and Databases
Authors: van Driel W.
Published: July 2016

For astronomers, monitoring of the radio spectrum is an obvious necessity in order to do observations which are free of interfering signals. Recent practice has shown that the installation of dedicated RFI surveillance antennas at radio astronomy sites has virtually become a necessity. Data obtained with such antennas have carried significant weight in discussions with other radio spectrum users. Furthermore, the growing number of dedicated antennas for RFI surveillance at radio observatories has opened the possibility for the establishment of common RFI databases. Such databases can provide objective numbers showing the degradation of the effective use of protected frequencies due to interference, to be used by astronomers as well as by their partners in frequency protection. As it is all too easy to drown in such a sea of data, discussions between astronomers themselves and with their partners are clearly necessary to define the form, implementation and use of such databases.
Low Temperature Experiments on Gas-Phase Chemical Processes
Authors: Rowe B. R. , Rowe C. Rebrion , Canosa A.
Published: July 2016

A review of the most recent experimental results concerning reaction kinetics at low temperatures is presented, most of them having been obtained using the CRESU technique. Some astrochemical consequences are also highlighted.
Millimeter Observations of Molecules in the Envelopes around Late-type Stars
Authors: Guélin Michel , Lucas Robert , Neri Roberto , Bremer Michael , Broguière Dominique
Published: July 2016

The envelopes surrounding AGB stars are similar to interstellar dark clouds in many respects; opaque to the visible light, they are transparent to mm wavelengths. Several envelopes, close enough to be spatially resolved with mm-wave interferometers, exhibit a remarkably rich molecular content, which can then be studied in detail as a function of radius. Because the envelopes are in expansion, their outer layers are older and more evolved than the inner ones, making it possible, thanks to a relatively simple geometry, to probe the time-dependence of the ongoing chemical processes.
New Developments in Inner Solar Nebula Chemistry
Authors: Kress Monika E.
Published: July 2016

The molecular cloud material which became the asteroids, meteorites and inner planets was extensively processed in the inner solar nebula. The chemical complexity of the most ancient meteorites attests to the highly nonequilibrium nature of the chemistry in this region, particularly regarding the volatile elements. Theoretical models describing the time evolution of the temperature and density profiles of protoplanetary accretion disks have recently become available. Such models provide a realistic framework within which to study, for instance, the effects of lightning and surface-catalyzed (gas-grain) reactions in the inner nebula. Here, we show that the latter would have been most efficient during the meteorite-forming epoch of the nebula, at the present position of the asteroid belt.
The Superbubble Model for LiBeB Production and Galactic Evolution
Authors: Parizot Etienne , Drury Luke
Published: July 2016

We show that the available constraints relating to 6LiBeB Galactic evolution can be accounted for by the so-called superbubble model, according to which particles are efficiently accelerated inside superbubbles out of a mixture of supernova ejecta and ambient interstellar medium. The corresponding energy spectrum is required to be flat at low energy (in E−1 below 500 MeV/n, say), as expected from Bykov's acceleration mechanism. The only free parameter is also found to have the value expected from standard SB dynamical evolution models. Our model predicts a slope 1 (primary) and a slope 2 (secondary) behaviour at respectively low and high metallicity, with all intermediate slopes achieved in the transition region, between 10−2 and 10−1Z⊙.
Sinks of Light Elements in Stars - Part II
Authors: Pinsonneault Marc H. , Charbonnel Corinne , Deliyannis Constantine P.
Published: July 2016

See the abstract given in Part I (Deliyannis, Pinsonneault, Charbonnel, hereafter DPC, in these proceedings). In Part II we discuss the lithium data for metal-poor stars and the constraints it places on stellar depletion. There are a variety of indicators that place interesting bounds on the degree of stellar depletion, and in contrast to the other two sections the data for Population II stars provides weaker evidence for stellar lithium depletion. We review both the theoretical studies and the observational data, and critically evaluate the degree of stellar depletion consistent with the data.
Constraints from Big Bang Nucleosynthesis on a Time-Varying Cosmological Constant
Authors: Lima J. A. S. , Maia J. M. F. , Pires N.
Published: July 2016

The limits from big bang nucleosynthesis on a class of models with time-varying A-term are reexamined. In particular, it is discussed how the stringent bounds previously derived may be relaxed.
The Deuterium Abundance In The Galactic Center 50 km/s Molecular Cloud: Evidence For A Cosmological Origin Of D
Authors: Lubowich D. A. , Pasachoff Jay M. , Galloway Robert P. , Balonek Thomas J. , Tremonti Christy , Millar Tom , Roberts Helen
Published: July 2016

We confirm that deuterium exists in the Galactic Center (GC) and estimate that D/H = 3 × 10−6 using a new 5192-chemical reaction model. This is the lowest D/H ratio observed in the Galaxy, five times lower than the local ISM D/H = 1.5 × 10−5 but 106 × larger than D/H predicted by GC models. We detected DCN in the GC Sgr A 50 km/s molecular cloud located 10 pc from the GC with the NRAO 12m telescope and obtained T*R = 0.061 ± 0.007 K and 0.04 ± 0.02 K for the J = 1-0 and 2-1 lines. The most likely source of the GC D is continuous injection from the infall of primordial matter with D/H = 5 × 10−5 with the D/H determined by astration and mixing. Thus there are no significant Galactic sources of D and no recent quasar or AGN activity in the GC. This primordial D/H implies that the baryon density is less than the density necessary to close the Universe; most of the baryons are in dark matter; and there are fewer than four ν families.
The Primordial 3-Helium Abundance At Last?
Authors: Bania T. M. , Rood Robert T. , Balser Dana S.
Published: July 2016

We summarize the past 17 years of our efforts to determine the cosmic abundance of the 3He isotope. The vast majority of our 3He+ observations were made with the NRAO 140 Foot telescope in Green Bank, WV. The 140 Foot ceased operations in July 1999 so that NRAO could prepare to commission its replacement, the Green Bank Telescope (GBT). Our 3He experiment was the last scientific program at the 140 Foot. It is thus poignant and timely for us to reassess the astrophysical context of our 3He results. Here we argue that the existence of “The 3He Plateau” for our sample of simple sources and recent advances in the understanding of the evolution of solar analog stars together suggest that we can finally estimate the primordial abundance of 3He. Our current best estimate for the primordial abundance is 3He/H = (1.5 ±0.6) × 10−5 (s.e.) by number.
Lithium in the Old Open Cluster NGC 2243
Authors: Hill V. , Pasquini L.
Published: July 2016

We report observations of lithium in a sample of 11 stars in the metal-poor open cluster NGC 2243, that were obtained from high-resolution spectroscopy at CASPEC (ESO 3.6m telescope). The targets are located at the turnoff region, plus one red giant star.

NGC 2243 is one of the most metal-poor open cluster, almost as deficient as 47 Tuc, but substantially younger (∼4 Gyrs and [Fe/H]=-0.5 dex), which makes it a very interesting case to compare with more metal rich coeval clusters on the one hand, and old metal-rich globular clusters (47 Tuc) on the other hand. The preliminary Lithium abundances obtained are discussed in this framework.
Lithium in Binary Systems with Evolved Components
Authors: Costa J. M. , Silva L. da , De Medeiros J. R.
Published: July 2016

The analysis of 72 binaries with component of luminosity class III shows that the behavior of Li abundance in such systems follows the same pattern presented by their single counterparts. Binarity seems to affect the lithium dilution in systems presenting orbital period lower than about 100 days.
Lithium and Rotation on the Subgiant Branch. A Theoretical Analysis of Observations
Authors: do Nascimento J. D. , Charbonnel C. , Lèbre A. , De Laverny P. , de Medeiros J. R.
Published: July 2016

Lithium abundances, determined for 120 subgiant stars in Lèbre et al. (1999), are analyzed and compared with predictions for dilution. To this purpose, the evolutionary status of the sample as well as the individual masses have been determined. We look for the distributions of A(Li) and Vsini with mass when those stars evolve along the subgiant branch. Our results bring a new light on the Lithium and rotation discontinuities in evolved phases.
Lithium Abundances in Bright Giant Stars
Authors: Lèbre Agnès , de Laverny Patrick , de Medeiros José Renan
Published: July 2016

We present new high resolution spectroscopic data of the 6707.81 Å Li I line for 117 G and K Bright Giants (class of luminosity II). We derived Lithium abundances that we analysed along the stellar parameters: Teff, M* and Vsini. With the CORAVEL spectrometers (at Observatoire de Haute Provence [OHP] and at European Southern Observatory [ESO]), De Medeiros & Mayor (2000) obtained radial velocities and Vsini with an uncertainty of about 0.3 kms—1 and 2.0 kms—1, respectively. CORAVEL data also provide indication on the binary nature of our sample stars (32% are binary stars).
Beryllium in the Sun: Re-Measurement and Implications
Authors: C. Balachandran Suchitra
Published: July 2016

The solar beryllium abundance is important because it provides a constraint on the depth to which mixing has occurred below the surface convective zone. Unlike helioseismology which only maps the present-day Sun, the solar beryllium abundance provides an integrated picture of mixing over the entire history of the Sun. In this review I outline the logic involving the ‘missing UV opacity’ that required that the solar beryllium abundance be re-determined. A brief summary of the empirical process of estimating the “missing UV opacity” is given along with a confirmation based on a recent re-calculation of the Fe I bound-free opacity. The addition of this opacity resulted in our finding that the solar beryllium abundance was meteoritic. The implications of this result in the context of mixing in solar-type stars is discussed.
The Galactic Evolution of Beryllium
Authors: Boesgaard Ann Merchant
Published: July 2016

The abundance of beryllium has been determined in unevolved stars over a range metal abundances in order to enhance our understanding of the chemical evolution of our Galaxy, cosmic-ray theory, and cosmology. Observations of 27 stars have been made with Keck I with HIRES at high spectral resolution (45,000) and high signal-to-noise ratios (60 - 110 typically). We find a remarkably linear relationship between log N(Be/H) and [Fe/H] with a slope of 0.96 (±0.04). Similarly, the relationship between log N(Be/H) and [O/H] is linear with a slope of 1.45 (±0.04). Beryllium increases at the same rate as Fe, but much faster than O. This provides constraints for and insights into models of Galactic chemical evolution. There is some evidence for an intrinsic spread in Be at a given [O/H] or [Fe/H]. There is no evidence of a plateau in Be at the lowest metallicities down to log N(Be/H) = —13.5.
Constraints on Stellar Hydrodynamics from Abundance Anomalies of LiBeB and Metals
Authors: Michaud Georges , Richer Jacques , Richard Olivier
Published: July 2016

The availability of large atomic data bases has made it possible to calculate stellar evolution models taking into detailed account the atomic diffusion of all important contributors to opacity. The radiative accelerations and the opacity are continuously calculated during evolution taking the abundance changes of 28 species into account. This leads to the first self-consistent stellar evolution models for A and F stars. In A and F stars an iron-peak convection zone appears.

The calculated abundance anomalies are very similar to those observed in AmFm stars in open clusters except that they are larger by a factor of about 3. To reduce the calculated anomalies to the observed ones, an additional source of turbulence (or some other hydrodynamical process) must be introduced. The mixed zone must extend about 5 times deeper than the iron convection zone. Detailed comparisons to a few AmFm stars have been carried out.

The LiBeB abundances observed in clusters give additional information. The abundances of the 28 species offer considerable constraints on the models. Various potential turbulence models have been introduced in a stellar evolution code and results of evolutionary calculations for Li gap stars are discussed in the light of the constraints offered by the abundances of LiBeB and metals. The radiative accelerations of LiBeB have also been recalculated taking the effect of changing metal abundances into account. This modifies the expected Li gap in the absence of turbulence.
Lithium Abundances in Solar-Type Stars
Authors: da Silva L. , Porto de Mello G. F.
Published: July 2016

We report Li abundances from the λ6707 line for 19 nearby dwarf and subgiant solar-type stars. The unevolved stars in this sample present high (> 2.00) Li abundances. We found a few cases of subgiant stars which present high Li content. The Sun seems to be part of a population of nearly unevolved stars which have depleted their Li to a high degree: all other metal-normal, near ZAMS stars in our sample show higher than solar Li content. There seems to be no correlation of the degree of Li depletion with mass, atmospheric parameters or state of evolution: as an example we found a star (HR1532) almost identical to the Sun in its state of evolution and atmospheric parameters, but with over ten times the solar Li abundance. We propose that different histories of angular momentum distribution at star birth, and/or post-birth angular momentum evolution, may account for these differences.
The Ideal Stars for Exploration of Early-Epoch 7Li Abundances
Authors: Rossi Silvia , C. Beers Timothy
Published: July 2016

We discuss estimates of stellar temperature, and the assemblage of a ‘critical set’ of target low-metallicity stars, from the HK Survey of Beers and collaborators, that can be used in the near future to put additional strong constraints on models for lithium production in the early Galaxy, and for inference of its primordial value.
On the Formation of Lithium Emission Lines in Nova Shells
Authors: Diaz Marcos
Published: July 2016

The role of nova outbursts in the galactic lithium production is still controversial. Photoionization model calculations of nova shells are presented in this contribution, aiming to identify the optimal post-outburst phase for detecting lithium emission lines from nova ejecta which may confirm its lithium enhancement. Predictions for the Li I λ6708 Â flux are made as a function of the envelope geometry, its physical parameters and properties of the central ionizing source.
The Evolution of 4He and LiBeB
Authors: A. Olive Keith
Published: July 2016

Our understanding of the evolution of 4He and 7Li depends critically on the available data for these two elements at low metallicity. In particular, the degree to which there is a slope in an abundance vs metallicity regression can help determine the evolution of He, C, N, and O in dwarf galaxies in the case of 4He, and cosmic-ray induced nucleosynthesis of LiBeB in our own galaxy in the case of 7Li. Recent data and their implications will be discussed.
Conclusions I
Authors: J. Pagel B. E.
Published: July 2016

Some conclusions are drawn from the Conference as to Big Bang Nucleosynthesis, cosmic rays, AGB star evolution and various kinds of mixing processes in stars.
Probes of Low Surface Brightness Galaxies through Low Frequency Spectroscopy with GMRT
Authors: Narasimha D. , Chitre S.M.
Published: July 2016

Low Surface Brightness galaxies (LSBs) may well constitute an important component of the Universe and a good fraction of baryons may even be locked up in their gravitational potential. Existence of such massive objects was predicted from an investigation of gravitational lens systems more than a decade ago (Narasimha & Chitre, 1989). There are more compelling reasons for believing their universality based on the of the analysis of the images around the cusp caustics in some of the well-studied lenses. A complete sample of the mass, size and rotation velocity of LSBs in our neighbourhood, as well as in a limited volume at a larger redshift will be important for estimation of power spectrum as well as evolution of structures in the Universe. The GMRT type instrument is ideally suited for detection and study of the LSBs. We expect to detect 21 cm emission from around 2 to 10 LSBs per beam of GMRT dish at the level of 5 mJy flux with a survey covering 30 Mhz bandwidth, if their line width is of the order of 30 km/sec.
Using Gravitational Lenses to Probe HI at High z
Authors: Saini T.D. , Sethi S.K. , Bharadwaj S.
Published: July 2016

We investigate the possibility of detecting damped Lyman-α systems at high redshifts using GMRT if these clouds are magnified by intervening cluster lenses. We show that if the HI mass of the damped clouds ≥ 2 × 1010 M⊙ then they can be detected with a probability ≥ 0.2 using GMRT.
HI absorption in Radio Galaxies
Authors: Morganti R. , Oosterloo T.A. , van Moorsel G. , Tadhunter C.N. , Killeen N.
Published: July 2016

Twenty-two powerful radio galaxies have been searched for HI absorption. We find the highest probability of detecting HI in absorption among narrow-line compact (or small) galaxies or galaxies with indication of richer interstellar medium (i.e. with ongoing or recent star-formation). We discuss the difficulty in the interpretation of the origin of the HI absorption due to the uncertainty in the systemic velocity of the galaxies.
Observational Properties of Diffuse Halos in Clusters
Authors: Feretti Luigina
Published: July 2016

The number of known diffuse radio sources in clusters of galaxies has grown in recent years, making it possible to derive statistical properties of these sources and of the hosting clusters. We show that diffuse sources are associated with X-ray luminous clusters which have undergone recent merger processes. The radio and X-ray structures are often similar, and correlations are found between radio and X-ray parameters. This is indication of a link between the diffuse relativistic and thermal plasma in clusters of galaxies.
Active Galaxies and Candidate Remnants in the Core of the Shapley Concentration
Authors: Venturi T. , Bardelli S. , Dallacasa D. , Hunstead R.W. , Morganti R. , Tzioumis T.
Published: July 2016

We present preliminary results of a multifrequency and multiresolution study carried out with the Australia Telescope Compact Array for nine of the ten extended radio galaxies located in the merging cluster complexes A3558 and A3528, at the centre of the Shapley Concentration. We found that 5 out of the 9 extended radio galaxies are active radio galaxies, i.e. they have a clear active radio nucleus coincident with the central region of the associated optical galaxy, radio jets and extended lobes; the remaining four lack an obvious radio nucleus, have a very diffuse and amorphous morphology and exhibit peculiar spectral properties. We call these radio sources as remnants and propose that they are (a) either radio galaxies where the nuclear activity has ceased; or (b) regions where pre-existing electrons have been reaccelerated as consequence of shocks due to cluster mergers.
Extended Extragalactic Radio Emission
Authors: Owen F.N. , Ledlow M.J. , Eilek J.A. , Kassim N.E. , Miller N. , Dwarakanath K.S. , Ivison R.J.
Published: July 2016

Extended radio emission and its relation to parent galaxy properties is briefly reviewed. Our current understanding of the relation between absolute radio and optical luminosity, radio morphology and linear size is discussed. The impact of radio jets on dense cluster cores is discussed using M87 as an example. Finally, the relation of AGN's to star-bursting galaxies at high redshift is considered.
Statistics of Giant Radio Sources
Authors: Machalski J. , Jamrozy M.
Published: July 2016

An important aspects of the studies of giant radio sources is that they can constrain models of the cosmological evolution of radio sources (e.g. Condon 1984, ApJ, 287, 461; Dunlop & Peacock 1990, MNRAS, 247, 19) and their host galaxies, as well as the recent analytical models of time evolution of these sources (e.g. Kaiser, Dennett—Thorpe & Alexander 1997, MNRAS, 292, 723; Blundell et al. 1999, AJ, 117, 677). In order to achieve these goals, we undertook the following tasks:
Physical Conditions in CSS Radio Sources
Authors: Tyul'bashev S. A. , Tchernikov P. A.
Published: July 2016

Interplanetary scintillation observations of 56 compact steep-spectrum radio sources have been carried out at 102 MHz on the Large Phased Array. Observations have shown that 42 sources have low frequency cut-offs in their spectra. The physical conditions in the compact components of the quasars and radio galaxies studied are estimated.
Outflows and the Disk-Halo Connection in Galaxies
Authors: A. Irwin Judith
Published: July 2016

There is now abundant evidence for high latitude gas in the Milky Way and external edge-on galaxies. The halo gas is seen in various ISM tracers, including HI, Hα, and radio continuum, and shows considerable structure, including discrete features which span the disk-halo interface. While some correlation with underlying star formation activity has been observed, several energy discrepancies are outlined which suggest that conventional processes related to massive star formation are not sufficient to account for the observed emission. Indeed, new sensitive data are showing that high latitude gas may be a common characteristic of all galaxies, not just those with high star formation rates.
Radio Spectra of Complete Sample of Galactic Supernova Remnants
Authors: Trushkin S.A.
Published: July 2016

We present radio continuum spectra for nearly 200 Galactic supernova remnants (SNRs) from 220 known and included in Green's (1998) catalog. Spectra plotting is an “on—line” procedure of the CATS database http://cats.sao.ru/ and it could plot quite accurate spectra with the thermal plasma free—free absorption in fitting the spectra accounted for: to indicate the presence of extended ionized medium along the line of sight.

We did not find considerable correlation between spectral index and Galactic coordinates l, b of SNRs. An analysis of 190 spectra showed that 78 SNRs (40 %) have clear low-frequency turnover caused, apparently, by absorption in the thermal foreground of the Milky Way. The turnover frequency vτ=1 for these SNRs has mean value near 30 MHz do not correlate with the Galactic coordinates. But the frequency has significant correlation with the distance to SNR, defined from ∑ — D relation.