- ID:
- ivo://nasa.heasarc/osrilqxray
- Title:
- Optically Selected Radio-Intermediate and Loud Quasars X-ray Emission Catalog
- Short Name:
- OSRILQXRAY
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This catalog contains some of the results of an investigation into the X-ray properties of radio-intermediate and radio-loud quasars (RIQs and RLQs, respectively). The authors have combined large, modern optical (e.g., SDSS) and radio (e.g., FIRST) surveys with archival X-ray data from Chandra, XMM-Newton, and ROSAT to generate an optically selected sample that includes 188 RIQs and 603 RLQs. This sample is constructed independently of X-ray properties but has a high X-ray detection rate (85%); it provides broad and dense coverage of the luminosity-redshift (l-z) plane, including at high redshifts (22% of the objects have z = 2-5), and it extends to high radio-loudness R<sub>L</sub> values (33% of objects have R<sub>L</sub> = log(L<sub>r</sub>/L<sub>o</sub>) = 3 - 5), where L<sub>r</sub> and L<sub>o</sub> are the rest-frame monochromatic luminosities at 5 GHz and 2500 Angstroms, respectively). The authors measure the "excess" X-ray luminosity of RIQs and RLQs relative to radio-quiet quasars (RQQs) as a function of radio loudness and luminosity, and parametrize the X-ray luminosity of RIQs and RLQs both as a function of optical/UV luminosity and also as a joint function of optical/UV and radio luminosity. RIQs are only modestly X-ray bright relative to RQQs; it is only at high values of radio loudness (R<sub>L</sub> >~ 3.5) and radio luminosity that RLQs become strongly X-ray bright. This HEASARC table contains the primary sample from the reference paper. The authors consider three categories of quasars in this work: RQQs, RIQs, and RLQs (rather than just RQQs and RLQs), where the define RIQs to consist of objects with 1 <= R<sub>L</sub> < 2; consequently, the objects they classify as RLQs satisfy R<sub>L</sub> >= 2. The primary sample contained herein consists of 654 optically selected RIQs and RLQs with SDSS/FIRST observations and high-quality X-ray coverage from Chandra (171), XMM-Newton (202), or ROSAT (281). The primary sample is split nearly evenly between spectroscopic (312) and high-confidence photometric (342) quasars. Most (562) of the primary sample objects possess serendipitous off-axis X-ray coverage, while the remainder (92) were targeted in the observations used in this sample. The X-ray detection fraction for the primary sample is 84%; the detection fraction for those objects with Chandra/XMM-Newton/ROSAT coverage is 95%/92%/70% (typical ROSAT observations are comparatively less sensitive and have higher background). The authors adopt a standard cosmology with H<sub>0</sub> = 70 km s<sup>-1</sup> Mpc<sup>-1</sup>, Omega<sub>M</sub> = 0.3, and Omega<sub>Lambda</sub> = 0.7 throughout their study. This table was created by the HEASARC in October 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/726/20">CDS Catalog J/ApJ/726/20</a> file table1.dat. This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/romabzcat
- Title:
- Roma-BZCAT Multi-Frequency Catalog of Blazars
- Short Name:
- ROMABZCAT
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the 5th edition of the Roma-BZCAT catalog of blazars which contains coordinates and multi-frequency data of 3561 sources. It presents several relevant changes with respect to the past editions which are briefly described in the reference paper. The Roma-BZCAT catalog contains data on 3561 sources, about 30% more than in the 1st edition, which either confirmed blazars or exhibiting characteristics close to this type of sources. With respect to the previous editions, this new edition has relevant changes in the sources' classification. The authors emphasize that all the sources in the Roma-BZCAT have a detection in the radio band. Moreover, complete spectroscopic information is published and could be accessed by the authors for all of them, with the exception of BL Lac candidates. Consequently, peculiar sources such as the so called "radio quiet BL Lacs", which are reported in some other catalogs, are not included here because of possible contamination by hot stars and other extragalactic objects. In the 5th edition, the authors use a similar denomination for the blazars to that adopted in the previous editions. Each blazar is identified by a code, with 5BZ for all blazars, a fourth letter that specifies the type (B, G, Q or U), followed by the truncated equatorial coordinates (J2000). The authors introduced the edition number before the letters BZ to avoid possible confusion due to the fact that several sources changed their old names because of a newly adopted classification. The 5th edition contains 1151 BZB sources (92 of which are reported as candidates because their optical spectra could not be found in the literature), 1909 BZQ sources, 274 BZG sources, and 227 BZU objects. This database table was originally ingested by the HEASARC in September 2013, based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/495/691">CDS Catalog J/A+A/495/691</a> file bzcat4.dat. It was updated in March 2016, and it is now based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/274">CDS Catalog VII/274</a> file bzcat5.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/rassbscpgc
- Title:
- ROSAT All-Sky Survey Bright Source Catalog/Catalog of Principal Galaxies Matches
- Short Name:
- RASSBSCPGC
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- In a correlation study of the ROSAT All-Sky Survey Bright Source Catalog (RASS-BSC, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/XI/10">CDS Cat. <XI/10></a>, the HEASARC table RASSBSC) with the Catalogue of Principal Galaxies (PGC, <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/119">CDS Cat. <VII/119></a>, the HEASARC table PGC2003), 904 X-ray sources were found that possess possible extragalactic counterparts within a search radius of 100 arcseconds. A visual screening process was applied to classify the reliability of the correlations. 547 correlations have been quoted as reliable identifications. From these, 349 sources are known to be active galaxies. Although for the other sources no hints for activity were found in the literature, 69% of those for which we have distances show X-ray luminosities exceeding those of normal galaxies, a clear sign that these galaxies also own hitherto unreported X-ray active components. Some objects are located inside or in the direction of a known group or cluster of galaxies. Their X-ray flux may therefore be in part affected by hot gas emission. In the paper, luminosity and log N-log S distributions are used to characterize different subsamples. Nuclei that are both optically and X-ray active are found predominantly in spirals. Two special source samples are defined, one with candidates for X-ray emission from hitherto unknown groups or clusters of galaxies, and one with high X-ray luminosity sources, that are likely candidates to possess hitherto unreported active galactic nuclei. Besides a compilation of X-ray and optical parameters, X-ray overlays on optical images for all the objects are also supplied as part of this work. This table contains 1124 optical galaxy entries for the 904 relevant X-ray candidates/counterparts from the RASS. Besides a compilation of X-ray and optical parameters for each source, the results of an identification screening are also given. The 904 optical images with X-ray overlay contours (xID_nnn.ps.gz) used in the screening process are added for each user's own judgement of the reliability of the associations. This table was created by the HEASARC in March 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/378/30">CDS catalog J/A+A/378/30</a> file table1.dat, the list of PGC galaxies identified as possible counterparts to RASS Bright Source Catalog X-ray sources. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sbsggencat
- Title:
- Second Byurakan Survey General Catalog Galaxies Optical Database
- Short Name:
- SBSGGENCAT
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Second Byurakan Survey (SBS) is a continuation of the First Byurakan Survey (FBS), also known as the Markarian Survey. The goal of the SBS was to reach fainter objects (as faint as limiting photographic magnitudes of 19.5, about 2.5 magnitudes fainter than the Markarian survey) and discover new active and star-forming galaxies using both UV excess and emission-line techniques. In this table, a database for the entire catalog of the Second Byurakan Survey (SBS) galaxies is presented, i.e, the 1700 SBS stars listed in Stepanian (2005) are not included herein. It contains new measurements of their optical parameters and additional information taken from the literature and other databases. The measurements were made using I<sub>pg</sub> (near-infrared), F<sub>pg</sub> (red) and J<sub>pg</sub> (blue) band images from photographic sky survey plates obtained by the Palomar Schmidt telescope and extracted from the STScI Digital Sky Survey (DSS). The database provides accurate coordinates, morphological type, spectral and activity classes, apparent magnitudes and diameters, axial ratios, and position angles, as well as number counts of neighboring objects in circles of radii 50 kpc around the sources. The total number of individual SBS objects in the database is now 1676. The 188 Markarian galaxies which were re-discovered by the SBS are not included in this database. the authors also include redshifts that are now available for 1576 SBS objects, as well as 2MASS infrared magnitudes for 1117 SBS galaxies. The new optical information on the SBS galaxies was obtained from images extracted from the STScI Digitized Sky Survey (DSS) of F_pg (red), J_pg (blue) and I_pg (near-infared) band photographic sky survey plates obtained by the Palomar telescope. This table was created by the HEASARC in May 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/VII/264">CDS Catalog J/VII/264</a> file sbs.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/neargalcat
- Title:
- Updated Nearby Galaxy Catalog
- Short Name:
- NEARGALCAT
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains an all-sky catalog of 869 nearby galaxies having individual distance estimates within 11 Mpc or corrected radial velocities relative to the Local Group centroid V<sub>LG</sub> < 600 km s<sup>-1</sup>. The catalog is a renewed and expanded version of the previous Catalog of Neighboring Galaxies by Karachentsev et al. (2004, AJ, 127, 2031). It collects data on the following galaxy observables: angular diameters, apparent magnitudes in the far-UV, B, and K<sub>s</sub> bands, H-alpha and H I fluxes, morphological types, H I-line widths, radial velocities, and distance estimates. In this Local Volume (LV) sample, 108 dwarf galaxies still remain without measured radial velocities. The catalog also lists calculated global galaxy parameters: the linear Holmberg diameters, absolute B magnitudes, surface brightnesses, H I masses, stellar masses estimated via K-band luminosity, H I rotational velocities corrected for galaxy inclination, indicative masses within the Holmberg radius, and three kinds of "tidal index" which quantify the local density environment. In the reference paper, the authors briefly discuss the Hubble flow within the LV and different scaling relations that characterize galaxy structure and global star formation in them. They also trace the behavior of the mean stellar mass density, H I-mass density, and star formation rate density within the volume considered. This table was created by the HEASARC in June 2013 based on electronic versions of Tables 1 and 2 from the reference paper which were obtained form the AJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/xmmcty2agn
- Title:
- XMM-COSMOS X-Ray Selected Type-2 AGN
- Short Name:
- XMMCTY2AGN
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the results from a study of the multi-wavelength (from the mid-infrared to the hard X-ray) properties of a sample of 255 spectroscopically identified X-ray selected Type-2 AGN from the XMM-COSMOS survey. Most of them are obscured and the X-ray absorbing column density is determined by either X-ray spectral analyses (for 45% of the sample), or from hardness ratios. Spectral energy distributions (SEDs) were computed for all sources in the sample. The average SEDs in the optical band are dominated by the host-galaxy light, especially at low X-ray luminosities and redshifts. There is also a trend between X-ray and mid-infrared luminosity: the AGN contribution in the infrared is higher at higher X-ray luminosities. The authors have calculated bolometric luminosities, bolometric corrections, stellar masses and star formation rates (SFRs) for these sources using multi-component modeling to properly disentangle the emission associated with stellar light from that due to black hole accretion. For 90% of the sample, they also have the morphological classifications obtained with an upgraded version of the Zurich estimator of structural types (ZEST+). The authors find that, on average, type-2 AGN have lower bolometric corrections than type-1 AGN. Moreover, they confirm that the morphologies of AGN host-galaxies indicate that there is a preference for these type-2 AGN to be hosted in bulge-dominated galaxies with stellar masses greater than 10<sup>10</sup> solar masses. For each source, this table contains the X-ray ID, spectroscopic redshift, logarithm of the 2-10keV luminosity, logarithm of the bolometric luminosity, bolometric correction, logarithm of the stellar mass, star formation rate, absolute magnitude M<sub>U</sub>, absolute magnitude M<sub>V</sub>, absolute magnitude M<sub>J</sub> (Johnson-Kron-Cousin system), and the morphological class. This table was created by the HEASARC in October 2011 based on CDS table J/A+A/534/A110 file table1.dat. Some of the values for the name parameter in the HEASARC's implementation of this table were corrected in April 2018. This is a service provided by NASA HEASARC .
