- ID:
- ivo://nasa.heasarc/skyview/sdssdr7
- Title:
- Sloan Digital Sky Survey g-band DR7
- Short Name:
- SDSSDR7
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Sloan Digital Sky Survey is the deepest large scale survey of the sky currently available. SkyView dynamically queries the SDSS archive to retrieve information and resample it into the user requested frame. Further information on the SDSS and many additional services are available at the <a href="https://www.sdss.org/">SDSS website</a>. Provenance: Sloan Digital Sky Survey Team. This is a service of NASA HEASARC.
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- ID:
- ivo://nasa.heasarc/sdsscvcat
- Title:
- Sloan Digital Sky Survey I/II Cataclysmic Variables Catalog
- Short Name:
- SDSSCVCAT
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The reference paper completed the series of cataclysmic variables (CVs) identified from the Sloan Digital Sky Survey (SDSS) I and II. The coordinates, magnitudes, and SDSS spectra of 33 more CVs were presented. Among the 33 are eight systems known prior to SDSS (CT Ser, DO Leo, HK Leo, IR Com, V849 Her, V405 Peg, PG1230+226, and HS0943+1404), as well as nine objects recently found through various photometric surveys. Among the systems identified since the SDSS are two polar candidates, two intermediate polar candidates, and one candidate for containing a pulsating white dwarf. A complete summary table of the 285 CVs with spectra from SDSS I/II which were listed in the reference paper and the 7 previous papers in the series is contained herein. This table was created by the HEASARC in January 2012 based on an electronic version of Table 6 from the reference paper which was obtained from the AJ web site. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sdssnbcqsc
- Title:
- Sloan Digital Sky Survey NBC Quasar Candidate Catalog
- Short Name:
- SDSSQSOCand.
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- The Nonparametric Bayes Classifier (NBC) Quasar Candidate Catalog is a catalog of 100,563 unresolved, UV-excess (UVX) quasar candidates with magnitudes to as faint as 21 in the g-band from 2099 square degrees of the Sloan Digital Sky Survey (SDSS) Data Release One (DR1) imaging data. Existing spectra of 22,737 sources reveals that 22,191 (97.6%) are quasars; accounting for the magnitude dependence of this efficiency, the authors estimate that 95,502 (95.0%) of the objects in the catalog are quasars. Such a high efficiency is unprecedented in broadband surveys of quasars. This "proof-of-concept" sample is designed to be maximally efficient, but still has 94.7% completeness to unresolved, g ~< 19.5, UVX quasars from the DR1 quasar catalog. This efficient and complete selection is the result of the application of a probability density type analysis to training sets that describe the four-dimensional color distribution of stars and spectroscopically confirmed quasars in the SDSS. Specifically, the authors use a nonparametric Bayesian classification, based on kernel density estimation, to parametrize the color distribution of astronomical sources - allowing for fast and robust classification. They further supplement the catalog by providing photometric redshifts and matches to FIRST/VLA, ROSAT, and USNO-B sources. 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 database table was created by the HEASARC in August 2005 based on CDS table J/ApJS/155/257/table1.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:
- 28 Mar 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:
- 28 Mar 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/sdsss82cxo
- Title:
- Sloan Digital Sky Survey Stripe 82 Chandra Source Match Catalog
- Short Name:
- SDSSS82CXO
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the data from the latest release of the Stripe 82 X-ray (82X) survey point-source catalog, which currently covers 31.3 deg<sup>2</sup> of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6,181 unique X-ray sources are significantly detected with XMM-Newton (> 5 sigma) and Chandra (> 4.5 sigma). This 31 deg<sup>2</sup> catalog release includes data from XMM-Newton cycle AO 13, which approximately doubled the Stripe 82X survey area. The flux limits of the Stripe 82X survey are 8.7 x 10<sup>-16</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, 4.7 x 10<sup>-15</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, and 2.1 x 10<sup>-15</sup> erg s<sup>-1</sup> cm^=2^ in the soft (0.5 - 2.0 keV), hard (2 - 10 keV), and full (0.5 - 10 keV) bands, respectively, with approximate half-area survey flux limits of 5.4 x 10<sup>-15</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, 2.9 x 10<sup>-14</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, and 1.7 x 10<sup>-14</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, respectively. The authors matched the X-ray source lists to available multi-wavelength catalogs, including updated matches to the previous release of the Stripe 82X survey; 88% of the sample is matched to a multi-wavelength counterpart. Due to the wide area of Stripe 82X and rich ancillary multi-wavelength data, including coadded SDSS photometry, mid-infrared WISE coverage, near-infrared coverage from UKIDSS and VISTA Hemisphere Survey (VHS), ultraviolet coverage from GALEX, radio coverage from FIRST, and far-infrared coverage from Herschel, as well as existing ~30% optical spectroscopic completeness, this study is beginning to uncover rare objects, such as obscured high-luminosity active galactic nuclei at high redshift. The Stripe 82X point source catalog is a valuable data set for constraining how this population grows and evolves, as well as for studying how they interact with the galaxies in which they live. The authors derive the XMM-Newton number counts distribution and compare it with their previously reported Chandra log N - log S relations and other X-ray surveys. Throughout this study, the authors adopt a cosmology of H<sub>0</sub> = 70 km s<sup>-1</sup> Mpc<sup>-1</sup>, Omega<sub>M</sub> = 0.27, and Lambda = 0.73. The XMM-Newton and Chandra X-ray sources were matched with sources in the SDSS, WISE, UKIDSS, VHS, GALEX, FIRST and Herschel databases using the maximum likelihood estimator (MLE) method, as discussed in detail in Section 4 of the reference paper. This table contains the list of 1,146 Chandra sources detected in the SDSS Stripe 82. A related table SDSSS82XMM contains the list of 5,220 XMM-Newton sources detected in the SDSS Stripe 82. This table was initially created by the HEASARC in April 2014 based on the machine-readable version of the table ('Properties of SDSS Quasars Detected by Chandra') described in Appendix B1 of the reference paper (LaMassa et al. 2013, MNRAS, 436, 3581) which was obtained from the CDS (their catalog J/MNRAS/436/3581/ file chands82.dat). The present version was created by the HEASARC in January 2017 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/817/172">CDS Catalog J/ApJ/817/172</a> file chandra.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sdsss82xmm
- Title:
- Sloan Digital Sky Survey Stripe 82 XMM-Newton Source Match Catalog
- Short Name:
- SDSSS82XMM
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains some of the data from the latest release of the Stripe 82 X-ray (82X) survey point-source catalog, which currently covers 31.3 deg<sup>2</sup> of the Sloan Digital Sky Survey (SDSS) Stripe 82 Legacy field. In total, 6,181 unique X-ray sources are significantly detected with XMM-Newton (> 5 sigma) and Chandra (> 4.5 sigma). This 31 deg<sup>2</sup> catalog release includes data from XMM-Newton cycle AO 13, which approximately doubled the Stripe 82X survey area. The flux limits of the Stripe 82X survey are 8.7 x 10<sup>-16</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, 4.7 x 10<sup>-15</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, and 2.1 x 10<sup>-15</sup> erg s<sup>-1</sup> cm^=2^ in the soft (0.5 - 2.0 keV), hard (2 - 10 keV), and full (0.5 - 10 keV) bands, respectively, with approximate half-area survey flux limits of 5.4 x 10<sup>-15</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, 2.9 x 10<sup>-14</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, and 1.7 x 10<sup>-14</sup> erg s<sup>-1</sup> cm<sup>-2</sup>, respectively. The authors matched the X-ray source lists to available multi-wavelength catalogs, including updated matches to the previous release of the Stripe 82X survey; 88% of the sample is matched to a multi-wavelength counterpart. Due to the wide area of Stripe 82X and rich ancillary multi-wavelength data, including coadded SDSS photometry, mid-infrared WISE coverage, near-infrared coverage from UKIDSS and VISTA Hemisphere Survey (VHS), ultraviolet coverage from GALEX, radio coverage from FIRST, and far-infrared coverage from Herschel, as well as existing ~30% optical spectroscopic completeness, this study is beginning to uncover rare objects, such as obscured high-luminosity active galactic nuclei at high redshift. The Stripe 82X point source catalog is a valuable data set for constraining how this population grows and evolves, as well as for studying how they interact with the galaxies in which they live. The authors derive the XMM-Newton number counts distribution and compare it with their previously reported Chandra log N - log S relations and other X-ray surveys. Throughout this study, the authors adopt a cosmology of H<sub>0</sub> = 70 km s<sup>-1</sup> Mpc<sup>-1</sup>, Omega<sub>M</sub> = 0.27, and Lambda = 0.73. The XMM-Newton and Chandra X-ray sources were matched with sources in the SDSS, WISE, UKIDSS, VHS, GALEX, FIRST and Herschel databases using the maximum likelihood estimator (MLE) method, as discussed in detail in Section 4 of the reference paper. This table contains the list of 5,220 sources detected in the SDSS Stripe 82 in archival, AO10 and AO13 XMM-Newton observations. A related table SDSSS82CXO contains the list of 1,146 Chandra sources detected in the SDSS Stripe 82. Compared to the initial version of this catalog based on the 2013 paper, in the current version of the catalog the MLE matching between the XMM-Newton archival and AO10 source lists and ancillary catalogs was updated to include a 1 arcsecond systematic error added in quadrature to the emldetect reported positional error. This table was initially created by the HEASARC in April 2014 based on the machine-readable version of the table ('Properties of SDSS Quasars Detected by XMM-Newton') described in Appendix B2 of the reference paper (LaMassa et al. 2013, MNRAS, 436, 3581) which was obtained from the CDS (catalog J/MNRAS/436/3581/, file xmms82.dat). The present version was created by the HEASARC in January 2017 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/ApJ/817/172">CDS catalog J/ApJ/817/172</a>, files xmmao10.dat and xmmao13.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sdsslasqso
- Title:
- Sloan Digital Sky Survey/UKIRT DSS Large Area Survey Matched Quasars Catalog
- Short Name:
- SDSSLASQSO
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- This table contains a catalog of over 130,000 quasar candidates with near-infrared (NIR) photometric properties, with an areal coverage of approximately 1200 deg<sup>2</sup>. This is achieved by matching the Sloan Digital Sky Survey (SDSS) in the optical ugriz bands to the UKIRT Infrared Digital Sky Survey (UKIDSS) Large Area Survey (LAS) in the NIR YJHK bands. The authors match the ~1 million SDSS DR6 Photometric Quasar catalog to Data Release 3 of the UKIDSS LAS (ULAS) and produce a catalog with 130,827 objects with detections in one or more NIR bands, of which 74,351 objects have optical and K-band detections and 42,133 objects have the full nine-band photometry. The majority (~85%) of the SDSS objects were not matched simply because these were not covered by the ULAS. The positional standard deviation of the SDSS Quasar to ULAS matches is 0.1370 arcseconds in RA and 0.1314 arcseconds in Dec. The authors find an absolute systematic astrometric offset between the SDSS Quasar catalog and the UKIDSS LAS, of |RA offset| = 0.025 arcseconds and |Dec offset| = 0.040 arcseconds; they suggest the nature of this offset to be due to the matching of catalog, rather than image, level data. Their matched catalog has a surface density of ~53 deg<sup>-2</sup> for K <= 18.27 objects; tests using this matched catalog, along with data from the UKIDSS Deep Extragalactic Survey, imply that its limiting magnitude is i ~ 20.6. Color-redshift diagrams, for the optical and NIR, show a close agreement between this matched catalog and recent quasar color models at redshift z <~ 2.0, while at higher redshifts, the models generally appear to be bluer than the mean observed quasar colors. This table was created by the HEASARC in September 2012 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/AJ/141/105">CDS Catalog J/AJ/141/105</a> file table4.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/sdssunuqsr
- Title:
- Sloan Digital Sky Survey Unusual Quasars Catalog
- Short Name:
- SDSSUNUQSR
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Large spectroscopic surveys have discovered very peculiar and hitherto unknown types of active galactic nuclei (AGN). Such rare objects may hold clues to the accretion history of the supermassive black holes at the centres of galaxies. The authors aim to create a sizeable sample of unusual quasars from the unprecedented spectroscopic database of the Sloan Digital Sky Survey (SDSS). This table contains a catalog of 1005 quasars with unusual spectra in the redshift interval from 0.6 to 4.3. [HEASARC Note: the redshifts in this table actually range from 0.497 to 4.771]. The quasars were selected from the Sloan Digital Sky Survey Data Release 7 (Abazajian et al., 2009, ApJS, 182, 543) by means of Kohonen self-organising maps. The spectra are dominated by either broad absorption lines (42%), unusual red continua (27%), weak emission lines (18%), or conspicuously strong optical and/or UV iron emission (11%). This large sample provides a useful resource for both studying properties and relations of/between different types of unusual quasars and selecting particularly interesting objects, even though the compilation is not aimed at completeness in a quantifiable sense. The spectra are grouped into seven types. The catalogue contains the redshift, the absolute magnitude, the spectral type, the radio loudness parameter, a peculiarity index, and some comments on peculiar spectral features. This table was created by the HEASARC in May 2012 based on CDS table J/A+A/541/A77 file table3.dat. This is a service provided by NASA HEASARC .
- ID:
- ivo://nasa.heasarc/agnsdssxmm
- Title:
- Sloan Digital Sky Survey/XMM-Newton AGN Spectral Properties Catalog
- Short Name:
- AGNSDSSXMM
- Date:
- 28 Mar 2025
- Publisher:
- NASA/GSFC HEASARC
- Description:
- Bright XMM-Newton data are combined with the Chandra Deep Field South observations to explore the behavior of the intrinsic AGN absorption, as a function of redshift and luminosity. The sample consists of 359 sources selected in the hard 2 - 8 keV band, spanning the flux range from 6 x 10<sup>-16</sup> - 3 x 10<sup>-13</sup> erg/cm<sup>2</sup>/s with a high rate of spectroscopic or photometric redshift completeness (100 and 85 percent for the Chandra and XMM-Newton data, respectively). The authors derive the column density values using X-ray spectral fits. They find that the fraction of obscured AGN falls with increasing luminosity in agreement with previous findings. The fraction of obscured AGN shows an apparent increase at high redshifts (z > 2). Simulations show that this effect can most probably be attributed to the fact that at high redshifts the column densities are overestimated. This table contains the subset of 153 brighter hard X-ray sources in the XMM-Newton/Sloan Digital Sky Survey (SDSS) sample which have 2-8 keV fluxes > 3 x 10<sup>-14</sup> erg cm<sup>-2</sup> s<sup>-1</sup>, excluding a number of sources with extended optical morphology and blue colors, as well as 4 sources with X-ray to optical fluxes < 0.1 which are fit better with stellar rather than QSO templates. 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 July 2007 based on <a href="https://cdsarc.cds.unistra.fr/ftp/cats/J/A+A/459/693">CDS Catalog J/A+A/459/693</a> file table2.dat. This is a service provided by NASA HEASARC .
