- ID:
- ivo://CDS.VizieR/J/ApJS/154/585
- Title:
- BATSE earth occultation deep sample results
- Short Name:
- J/ApJS/154/585
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Burst and Transient Source Experiment (BATSE), aboard the Compton Gamma Ray Observatory (CGRO), provided a record of the low-energy gamma-ray sky (~20-1000keV) between 1991 April and 2000 May (9.1yr). We performed a deep-sampling of 58 objects, plus a selection of 121 more objects, combining data from the entire 9.1yr BATSE data set. Source types considered were primarily accreting binaries, but a small number of representative active galaxies, X-ray-emitting stars, and supernova remnants were also included. The sample represents a compilation of sources monitored and/or discovered with BATSE and other high-energy instruments between 1991 and 2000, known sources taken from the HEAO 1 A-4 (1984ApJS...54..581L) and Macomb & Gehrels (1999ApJS..120..335M, Cat. <J/ApJS/120/335>) catalogs. Flux data for the deep sample are presented in four energy bands: 2040, 4070, 70160, and 160430keV. The limiting average flux level (9.1yr) for the sample varies from 3.5 to 20mcrab (5{sigma}) between 20 and 430keV, depending on systematic error, which in turn is primarily dependent on the sky location.
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- ID:
- ivo://CDS.VizieR/J/ApJS/126/19
- Title:
- BATSE gamma-ray burst spectral catalog. I.
- Short Name:
- J/ApJS/126/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first in a series of gamma-ray burst spectroscopy catalogs from the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory, each covering a different aspect of burst phenomenology. In this paper, we present time sequences of spectral fit parameters for 156 bursts selected for either their high peak flux or fluence. All bursts have at least eight spectra in excess of 45{sigma} above background and span burst durations from 1.66 to 278s. Individual spectral accumulations are typically 128ms long at the peak of the brightest events but can be as short as 16ms, depending on the type of data selected. We have used mostly high energy resolution data from the Large Area Detectors, covering an energy range of typically 28-1800keV. The spectral model chosen is from a small empirically determined set of functions, such as the well-known "GRB" function, that best fits the time-averaged burst spectra. Thus, there are generally three spectral shape parameters available for each of the 5500 total spectra: a low-energy power-law index, a characteristic break energy, and possibly a high-energy power-law index. We present the distributions of the observed sets of these parameters and comment on their implications.
- ID:
- ivo://CDS.VizieR/J/ApJ/740/104
- Title:
- BATSE GRB pulse catalog - preliminary data
- Short Name:
- J/ApJ/740/104
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We demonstrate that distinguishable gamma-ray burst (GRB) pulses exhibit similar behaviors as evidenced by correlations among the observable pulse properties of duration, peak luminosity, fluence, spectral hardness, energy-dependent lag, and asymmetry. Long and Short burst pulses exhibit these behaviors, suggesting that a similar process is responsible for producing all GRB pulses. That these properties correlate in the observer's frame indicates that intrinsic correlations are strong enough to not be diluted into insignificance by the dispersion in distances and redshift. We show how all correlated pulse characteristics can be explained by hard-to-soft pulse evolution, and we demonstrate that "intensity tracking" pulses not having these properties are not single pulses; they instead appear to be composed of two or more overlapping hard-to-soft pulses. In order to better understand pulse characteristics, we recognize that hard-to-soft evolution provides a more accurate definition of a pulse than its intensity variation. This realization, coupled with the observation that pulses begin near-simultaneously across a wide range of energies, leads us to conclude that the observed pulse emission represents the energy decay resulting from an initial injection, and that one simple and as yet unspecified physical mechanism is likely to be responsible for all GRB pulses regardless of the environment in which they form and, if GRBs originate from different progenitors, then of the progenitors that supply them with energy.
- ID:
- ivo://CDS.VizieR/J/ApJS/127/79
- Title:
- BATSE occultation catalog of Gamma-Ray sources
- Short Name:
- J/ApJS/127/79
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using the powerful Earth-occultation technique, long-term, nearly continuous monitoring of the entire low-energy gamma-ray sky is now possible with the advent of BATSE, the Burst and Transient Source Experiment on board the Compton Gamma Ray Observatory (CGRO). In this paper, we present a catalog of 34 moderately strong gamma-ray sources measured by BATSE. It consists of 0.03 - 1.8 MeV photon spectra averaged over weeks and months, and light curves of the 35 - 200 keV flux, with 1 day resolution, covering the first three phases of the CGRO mission (1991 May through 1994 October). This database contains a complete record of {~}1200 daily source count rates in 14 energy channels along with the corresponding Poisson and systematic errors.
- ID:
- ivo://CDS.VizieR/J/ApJ/855/101
- Title:
- BATSE TTE GRB pulse catalog
- Short Name:
- J/ApJ/855/101
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We analyze pulse properties of short gamma-ray bursts (GRBs) from a new catalog containing 434 pulses from 387 BATSE time-tagged event (TTE) GRBs. Short GRB pulses exhibit correlated properties of duration, fluence, hardness, and amplitude, and they evolve hard to soft while undergoing similar triple- peaked light curves similar to those found in long/intermediate bursts. We classify pulse light curves using their temporal complexities, demonstrating that short GRB pulses exhibit a range of complexities from smooth to highly variable. Most of the bright, hard, chaotic emission seen in complex pulses seems to represent a separate highly variable emission component. Unlike long/intermediate bursts, as many as 90% of short GRBs are single-pulsed. However, emission in short multipulsed bursts is coupled such that the first pulse's duration is a predictor of both the interpulse separation and subsequent pulse durations. These results strongly support the idea that external shocks produce the prompt emission seen in short GRBs. The similarities between the triple-peaked structures and spectral evolution of long, short, and intermediate GRBs then suggests that external shocks are responsible for the prompt emission observed in all GRB classes. In addition to these findings, we identify a new type of gamma-ray transient in which peak amplitudes occur at the end of the burst rather than at earlier times. Some of these "crescendo" bursts are preceded by rapid-fire "staccato" pulses, whereas the remaining are preceded by a variable episode that could be unresolved staccato pulses.
1676. BAT X-ray survey. I.
- ID:
- ivo://CDS.VizieR/J/ApJ/678/102
- Title:
- BAT X-ray survey. I.
- Short Name:
- J/ApJ/678/102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We applied the maximum likelihood (ML) method, as an image reconstruction algorithm, to the BAT (Burst Alert Telescope) X-Ray Survey (BXS). This method was specifically designed to preserve the full statistical information in the data and to avoid mosaicking of many exposures with different pointing directions, thus reducing systematic errors when co-adding images. We reconstructed, in the 14-170keV energy band, the image of a 90x90deg^2^ sky region, centered on (RA, DE)=(105{deg}, -25{deg}), which BAT surveyed with an exposure time of ~1Ms (in 2005 November). The best sensitivity in our image is ~0.85mCrab or 2.0x10^-11^ergs/cm^2^. We detect 49 hard X-ray sources above the 4.5{sigma} level; of these, only 12 were previously known as hard X-ray sources (>15keV). Swift XRT observations allowed us to firmly identify the counterparts for 15 objects, while 2 objects have Einstein IPC counterparts (Harris et al., 1990, in Imaging X-Ray Astronomy. A Decade of Achievements, ed. M. Elvis (Cambridge: Cambridge Univ. Press), 309); in addition to those, we found a likely counterpart for 13 objects by correlating our sample with the ROSAT All-Sky Survey Bright Source Catalog (Voges et al., 1999, Cat. <IX/10>). Seven objects remain unidentified.
1677. BAT X-ray Survey - III
- ID:
- ivo://CDS.VizieR/J/ApJ/673/96
- Title:
- BAT X-ray Survey - III
- Short Name:
- J/ApJ/673/96
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- In this concluding part of the series of three papers dedicated to the Swift BAT hard X-ray survey (BXS), we focus on the X-ray spectral analysis and statistical properties of the source sample. Using a dedicated method to extract time-averaged spectra of BAT sources, we show that Galactic sources have, generally, softer spectra than extragalactic objects and that Seyfert 2 galaxies are harder than Seyfert 1's.
- ID:
- ivo://CDS.VizieR/J/A+A/566/A10
- Title:
- Ba V, Ba VI, and Ba VII oscillator strengths
- Short Name:
- J/A+A/566/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- For the spectral analysis of high-resolution and high-signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Reliable Ba V-VII oscillator strengths are used to identify Ba lines in the spectra of the DA-type white dwarf G191-B2B and the DO-type white dwarf RE 0503-289 and to determine their photospheric Ba abundances. We newly calculated Ba V-VII oscillator strengths to consider their radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Ba lines exhibited in high-resolution and high-S/N UV observations of G191-B2B and RE 0503-289.
- ID:
- ivo://nasa.heasarc/baxgalclus
- Title:
- BAX X-Ray Galaxy Clusters and Groups Catalog
- Short Name:
- BAXGalClus
- Date:
- 14 Feb 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the BAX X-Ray Galaxy Clusters and Groups Catalog. BAX (`Base de Donnees Amas de Galaxies X': see <a href="http://bax.ast.obs-mip.fr/">http://bax.ast.obs-mip.fr/</a> for more details) is a multi-wavelength database dedicated to X-ray clusters and groups of galaxies which allows detailed information retrieval. BAX is designed to support astronomical research by providing access to published measurements of the main physical quantities and to the related bibliographic references: basic data stored in the database are cluster/group identifiers, equatorial coordinates, redshift, flux, X-ray luminosity (in the ROSAT band) and temperature, and (in the online version at <a href="http://bax.ast.obs-mip.fr/">http://bax.ast.obs-mip.fr/</a>) links to additional linked parameters (in X-rays, such as spatial profile parameters, as well as SZ parameters of the hot gas, lensing measurements, and data at other wavelengths, such as the optical and radio bands). The clusters and groups in the online BAX database can be queried by the basic parameters as well as the linked parameters or combinations of these. The authors expect BAX to become an important tool for the astronomical community. BAX will optimize various aspects of the scientific analysis of X-ray clusters and groups of galaxies, from proposal planning to data collection, interpretation and publication, from both ground based facilities like MEGACAM (CFHT), VIRMOS (VLT) and from space missions like XMM-Newton, Chandra and Planck. This table was created by the HEASARC in October 2004 based on CDS table B/bax/bax.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://CDS.VizieR/J/ApJ/898/27
- Title:
- Bayesian Ages For Field LowEr-mass Stars
- Short Name:
- J/ApJ/898/27
- Date:
- 07 Dec 2021 15:25:13
- Publisher:
- CDS
- Description:
- Age is a fundamental parameter of stars, yet in many cases, ages of individual stars are presented without robust estimates of the uncertainty. We have developed a Bayesian framework, BAFFLES, to produce the age posterior for a star from its calcium emission strength (log(R_HK_^'^)) or lithium abundance (Li EW) and B-V color. We empirically determine the likelihood functions for calcium and lithium as functions of age from literature measurements of stars in benchmark clusters with well-determined ages. We use a uniform prior on age, which reflects a uniform star formation rate. The age posteriors we derive for several test cases are consistent with literature ages found from other methods. BAFFLES represents a robust method to determine the age posterior probability distribution for any field star with 0.45<=B-V0.9 and a measurement of R_HK_^'^ and/or 0.35<=B-V<=1.9 and measured Li EW. We compile colors, R_HK_^'^, and Li EW from over 2630 nearby field stars from the literature, and present the derived BAFFLES age posterior for each star.
