- ID:
- ivo://nasa.heasarc/glxsdssqso
- Title:
- GALEX/SDSS Quasar Catalog
- Short Name:
- GLXSDSSQSO
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the result of an analysis of the broad-band UV and optical properties of z ~< 3.4 quasars matched in the Galaxy Evolution Explorer (GALEX) General Data Release 1 (GR1) and the Sloan Digital Sky Survey (SDSS) Data Release 3 (DR3). Of the 6371 SDSS DR3 quasars covered by 204 GALEX GR1 tiles and listed in this table, 5380 (84%) have near-UV detections, while 3034 (48%) have both near-UV and far-UV detections using a matching radius of 7 arcseconds. Most of the DR3 sample quasars are detected in the near-UV until z ~ 1.7, with the near-UV detection fraction dropping to ~50% by z ~ 2. Statistical tests performed on the distributions of non-detections indicate that the optically selected quasars missed in the UV tend to be optically faint or at high redshift. The GALEX positions are shown to be consistent with the SDSS astrometry to within an rms scatter of 0.6 - 0.7 arcsecs in each coordinate, and the empirically determined photometric errors from multi-epoch GALEX observations significantly exceed the Poissonian errors quoted in the GR1 object catalogs. The UV-detected quasars are well separated from stars in UV-optical color-color space, with the UV-optical relative colors suggesting a marginally detected population of reddened objects due to absorption along the line of sight or dust associated with the quasar. The resulting spectral energy distributions (SEDs) cover ~350 - 9000 Angstroms (rest frame), where the overall median SED peaks near the Lyman-Alpha emission line, as found in other UV quasar studies. The large sample size allows the authors to construct median SEDs in small bins of redshift and luminosity, and they find that the median SED becomes harder (bluer) at UV wavelengths for quasars with lower continuum luminosity. The detected UV-optical flux as a function of redshift is qualitatively consistent with attenuation by intervening Lyman-absorbing clouds. This table was created by the HEASARC in October 2009 based on the electronic version of Table 2 from the reference paper which was obtained from the CDS (their catalog J/AJ/133/1780 file table2.dat). This is a service provided by NASA HEASARC .
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- ID:
- ivo://nasa.heasarc/intagncat
- Title:
- Second INTEGRAL AGN Catalog
- Short Name:
- INTAGNCAT
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The INTEGRAL mission provides a large data set for studying the hard X-ray properties of AGN and allows testing the unified scheme for AGN. This table contains some of the results from the analysis of INTEGRAL IBIS/ISGRI, JEM-X, and OMC data for 199 AGN (and 3 clusters of galaxies) that have been reported to be detected by INTEGRAL at energies above 20 keV. The data analyzed therein allowed a significant spectral extraction on 148 objects and optical variability study of 57 AGN. The slopes of the hard X-ray spectra of Seyfert 1 and Seyfert 2 galaxies were found to be consistent within the uncertainties, whereas lower luminosities were measured for the more absorbed/type 2 AGN. The intermediate Seyfert 1.5 objects exhibit hard X-ray spectra consistent with those of Seyfert 1 galaxies. When applying a Compton reflection model, the underlying continua appear still the same in Seyfert 1 and 2 with photon index 2, and the reflection strength is about R = 1, when assuming different inclination angles. A significant correlation is found between the hard X-ray and optical luminosity and the mass of the central black hole, in the sense that the more luminous objects appear to be more massive. There is also a general trend for the absorbed sources and type 2 AGN to have lower Eddington ratios. The black hole mass appears to form a fundamental plane together with the optical and X-ray luminosity of the form L<sub>V</sub> being proportional to L<sub>X</sub><sup>0.6</sup> M<sub>BH</sub><sup>0.2</sup>, similar to that found between radio luminosity L<sub>R</sub>, L<sub>X</sub>, and M<sub>BH</sub>. The unified model for Seyfert galaxies seems to hold, showing in hard X-rays that the central engine is the same in Seyfert 1 and 2 but seen under different inclination angles and absorption. A catalog of 199 IBIS/ISGRI detected AGN is presented. For those 148 objects significantly detected in the data set analyzed here, spectral parameters, fluxes, and luminosities are given. In addition, the photometric table of OMC measurements in the V-band (given for 57 of the AGN) is also included herein. For objects with more complex spectra, notice, the results of a fit to a cut-off power law model were presented in Table 3 of the reference paper, but are not included in this HEASARC table. The JEM-X spectra of the 23 AGN detected by the X-ray monitor were fit with the IBIS/ISGRI data, and the results of this were presented in Table 4 of the reference paper, but are also not included in this HEASARC table. This table was created by the HEASARC in November 2009 based on the electronic version of Tables 1, 2 and 5 from the reference paper which was obtained from the CDS (their catalog J/A+A/505/417 files table1.dat, table2.dat and table5.dat). This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sdssquasar
- Title:
- Sloan Digital Sky Survey Quasar Catalog (Twelfth Data Release: DR12Q)
- Short Name:
- SDSS(QSO)
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains the Data Release 12 Quasar Catalog (DR12Q) from the Baryon Oscillation Spectroscopic Survey (BOSS) of the Sloan Digital Sky Survey III (SDSS-III). This catalog includes all SDSS-III/BOSS objects that were spectroscopically targeted as quasar candidates during the full survey and that are confirmed as quasars via visual inspection of the spectra, have luminosities M_i_[z=2] < -20.5 (in a LambdaCDM cosmology with H<sub>0</sub> = 70 km/s/Mpc, Omega<sub>M</sub> = 0.3, and Omega<sub>Lambda</sub> = 0.7), and either display at least one emission line with a full width at half maximum (FWHM) larger than 500 km/s or, if not, have interesting/complex absorption features. The catalog also includes previously known quasars (mostly from SDSS-I and II) that were re-observed by BOSS. The catalog contains 297,301 quasars (272,026 are new discoveries since the beginning of SDSS-III) detected over 9376 deg<sup>2</sup> with robust identification and redshift measured by a combination of principal component eigenspectra. The number of quasars with z > 2.15 (184,101, of which 167,742 are new discoveries) is about an order of magnitude greater than the number of z > 2.15 quasars known prior to BOSS. Redshifts and FWHMs are provided for the strongest emission lines (C IV, C III], Mg II). The catalog identifies 29,580 broad absorption line quasars and their characteristics are listed in the file dr12qbal.dat that is available at the CDS (<a href="http://cdsarc.u-strasbg.fr/ftp/cats/VII/279/">http://cdsarc.u-strasbg.fr/ftp/cats/VII/279/</a>). For each object, the catalog presents five-band (u, g, r, i, z) CCD-based photometry with typical accuracy of 0.03 mag together with some information on the optical morphology and the selection criteria. When available, the catalog also provides information on the optical variability of quasars using SDSS and Palomar Transient Factory multi-epoch photometry. The catalog also contains X-ray, ultraviolet, near-infrared, and radio emission properties of the quasars, when available, from other large-area surveys. The calibrated digital spectra, covering the wavelength region 3600-10,500 Angstrom at a spectral resolution in the range 1300 < R < 2500, can be retrieved from the SDSS Catalog Archive Server at <a href="http://www.sdss.org/dr12/data_access/">http://www.sdss.org/dr12/data_access/</a>. In their paper, the authors also provide a supplemental list of an additional 4,841 quasars that have been identified serendipitously outside of the superset defined to derive the main quasar catalog, available as the file dr12qsp.dat that is available at the CDS (<a href="http://cdsarc.u-strasbg.fr/ftp/cats/VII/279/">http://cdsarc.u-strasbg.fr/ftp/cats/VII/279/</a>). This table contains the final quasar catalog of the SDSS-III/BOSS survey resulting from five years of observations. The catalog, which the authors call "DR12Q", contains 297,301 quasars, 184,101 of which have z > 2.15. the authors provide robust identification from visual inspection and refined redshift measurements based on the result of a principal component analysis of the spectra. The present catalog contains about 80% more quasars than their previous release (Paris et al., 2014, "DR10Q", <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/270">CDS Cat. VII/270</a>). In SDSS-III, all fluxes in the 5 SDSS bands (u, g, r, i and z) are expressed in terms of "nanomaggies" (nMgy), which are a convenient linear unit. These quantities are related to standard AB magnitudes thus: an object with a flux F given in nMgy has a Pogson magnitude (on the AB scale) m = [22.5 mag] - 2.5*log<sub>10</sub>(F). A flux of 1 Mgy is therefore close to 3631 Jy, and 1 nMgy = ~3.631 uJy (µJy). This table was updated to DR12Q in July 2017 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/VII/279">CDS Catalog VII/279</a> file dr12q.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sdsscxoqso
- Title:
- Sloan Digital Sky Survey Quasars Detected by Chandra
- Short Name:
- SDSSCXOQSO
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have studied the spectral energy distributions and evolution of a large sample of optically selected quasars from the Sloan Digital Sky Survey (SDSS) that were observed in 323 Chandra images analyzed by the Chandra Multiwavelength Project (ChaMP). Their highest-confidence matched sample (which this HEASARC table comprises) includes 1135 X-ray detected quasars in the redshift range 0.2 < z < 5.4, representing some 36 Msec of effective exposure. In their paper, the authors provide catalogs of QSO properties, and describe their novel method of calculating X-ray flux upper limits and effective sky coverage. Spectroscopic redshifts are available for about 1/3 of the detected sample; elsewhere, redshifts are estimated photometrically. The authors have detected 56 QSOs with redshift z > 3, substantially expanding the known sample. They find no evidence for evolution out to z ~ 5 for either the X-ray photon index Gamma or for the ratio of optical/UV to X-ray flux Alpha_ox. About 10% of detected QSOs show best-fit intrinsic absorbing columns greater than 10<sup>22</sup> cm<sup>-2</sup>, but the fraction might reach ~1/3 if most nondetections are absorbed. The authors confirm a significant correlation between Alpha_ox and optical luminosity, but it flattens or disappears for fainter (M_B >~ -23) active galactic nucleus (AGN) alone. They report significant hardening of Gamma both toward higher X-ray luminosity, and for relatively X-ray loud quasars. These trends may represent a relative increase in nonthermal X-ray emission, and their findings thereby strengthen analogies between Galactic black hole binaries and AGN. For uniformly selected subsamples of narrow-line Seyfert 1s and narrow absorption line QSOs, they find no evidence for unusual distributions of either Alpha_ox or Gamma. Much more information on the SDSS is available at the project's web site at <a href="http://www.sdss.org/">http://www.sdss.org/</a>. This table was created by the HEASARC in April 2009 based on the machine-readable version of Table 2 ('Properties of SDSS Quasars Detected by Chandra') which was obtained from the ApJ website. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/swsdssqso
- Title:
- Swift Simultaneous UV, Optical, and X-Ray Observed Quasar Catalog
- Short Name:
- SWSDSSQSO
- Date:
- 18 Apr 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The authors have compiled a catalog of optically selected quasars with simultaneous observations in UV/optical and X-ray bands by the Swift Gamma-ray Burst Explorer. Objects in this catalog are identified by matching the Swift pointings with the Sloan Digital Sky Survey (SDSS) Data Release 5 (DR5) quasar catalog. The final catalog contains 843 objects, among which 637 have both Ultraviolet Optical Telescope (UVOT) and X-Ray Telescope (XRT) observations and 354 of which are detected by both instruments. The overall X-ray detection rate is ~ 60% which rises to ~ 85% among sources with at least 10 ks of XRT exposure time. The authors construct the time-averaged spectral energy distribution (SED) for each of the 354 quasars using UVOT photometric measurements and XRT spectra. From model fits to these SEDs, they find that the big blue bump contributes about ~ 0.3 dex to the quasar luminosity. The authors re-visit the alpha<sub>ox</sub> - L<sub>2500A</sub> relation by selecting a clean sample with only Type 1 radio-quiet quasars; the dispersion of this relation is reduced by at least 15% compared with studies that use non-simultaneous UV/optical and X-ray data. They find only a weak correlation between L<sub>bol</sub>/L<sub>Edd</sub> and alpha<sub>UV</sub>. They do not find significant correlations between alpha<sub>x</sub> and alpha<sub>ox</sub>, alpha<sub>ox</sub> and alpha<sub>UV</sub>, and alpha<sub>x</sub> and log L(0.3-10 keV). The correlations between alpha<sub>UV</sub> and alpha<sub>x</sub>, alpha<sub>ox</sub> and alpha<sub>x</sub>, alpha<sub>ox</sub> and alpha<sub>UV</sub>, L<sub>bol</sub>/L<sub>Edd</sub> and alpha<sub>x</sub>, and L<sub>bol</sub>/L<sub>Edd</sub> and alpha<sub>ox</sub> are stronger among low-redshift quasars, indicating that these correlations are likely driven by the changes of SED shape with accretion state. This quasar sample was compiled in the following steps: 1. Candidate objects for the catalog were selected as any SDSS DR5 quasar that lie within 20 arcminutes of the center of the Swift FOV in any pointing from launch through 2008 June. 2. XRT data were processed to obtain X-ray count rates, spectra, and spectral parameters. 3. UVOT data were processed to obtain UV and optical photometry. 4. UVOT photometry were supplemented with measurements at other wavelengths from published catalogs. 5. Quasar SEDs were constructed. 6. Additional parameters were calculated based on the SEDs of each quasar. The raw sample is constructed by matching 3.5 years Swift pointings and the SDSS DR5 quasar catalog and contains 1034 objects. This HEASARC version of this catalog contains all 1034 objects in the "raw" catalog. To select only the 843 objects in the "final" catalog, the user should specify catalog_flag = 1 in any searches of this table. This table was created by the HEASARC in August 2012 based on an electronic version of Table 8 from the reference paper which was obtained from the ApJS web site. This is a service provided by NASA HEASARC .
