SDSSXMMQSO ivo://nasa.heasarc/sdssxmmqso NASA/GSFC HEASARC Young et al. 2026-05-29 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov AGN This table contains the 5th Data Release Sloan Digital Sky Survey (DR5 SDSS)/XMM-Newton Quasar Survey Catalog. This catalog contains 792 SDSS DR5 quasars with optical spectra that have been observed serendipitously in the X-rays with XMM-Newton. These quasars cover a redshift range of z = 0.11 - 5.41 and a magnitude range of i = 15.3 - 20.7. Substantial numbers of radio-loud (70) and broad absorption line (51) quasars exist within this sample. Significant X-ray detections at >=2 sigma account for 87% of the sample (685 quasars), and 473 quasars are detected at >=6 sigma, sufficient to allow X-ray spectral fits. For detected sources, ~60% have X-ray fluxes between F(2-10 keV) = (1-10) x 10<sup>-14</sup> erg cm<sup>-2</sup> s<sup>-1</sup>. The authors fit a single power law, a fixed power law with intrinsic absorption left free to vary, and an absorbed power-law model to all quasars with X-ray signal-to-noise ratio >= 6, resulting in a weighted mean photon index Gamma = 1.91 +/- 0.08, with an intrinsic dispersion sigma(Gamma) = 0.38. For the 55 sources (11.6%) that prefer intrinsic absorption, the authors find a weighted mean N<sub>H</sub> = 1.5 +/- 0.3 x 10<sup>21</sup> cm<sup>-2</sup>. They find that Gamma correlates significantly with optical color, Delta(g-i), the optical-to-X-ray spectral index (alpha<sub>ox</sub>), and the X-ray luminosity. While the first two correlations can be explained as artifacts of undetected intrinsic absorption, the correlation between Gamma and X-ray luminosity appears to be a real physical correlation, indicating a pivot in the X-ray slope. This table was created by the HEASARC in July 2009 based on electronic versions of Tables 1 and 2 from the paper which were obtained from the Astrophysical Journal web site. This is a service provided by NASA HEASARC . 2009ApJS..183...17Y https://heasarc.gsfc.nasa.gov/W3Browse/all/sdssxmmqso.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=sdssxmmqso& GET text/xml 180 99999 true 20.105375 -10.91083333 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=sdssxmmqso GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_sdssxmmqso&Action=More+Options&Action=Parameter+Search&ConeAdd=1 SDSS 0.0166666666666667 X-ray public sdssxmmqso Sloan Digital Sky Survey (DR5)/XMM-Newton Quasar Survey Catalog name Source Designation meta.id;meta.main char nullable xmm_obsid XMM-Newton Observation Identifier meta.id;obs char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable counts Net Source Counts ct phot;em.X-ray double nullable snr X-Ray Signal-to-Noise Ratio stat.snr double nullable rest_frame_sb_lx Rest-Frame Luminosity in 0.5-2 keV Band erg/s phys.luminosity;em.X-ray.soft double nullable rest_frame_hb_lx Rest-Frame Luminosity in 2-10 keV Band erg/s phys.luminosity;em.X-ray.medium double nullable "__x_ra_dec" System unit vector column double nullable "__y_ra_dec" System unit vector column double nullable "__z_ra_dec" System unit vector column double nullable "__row" System index column char nullable spectral_index X-Ray Photon Index for Best-Fit Model spect.index double nullable chi_squared Chi-Squared Value for Best-Fit Model stat.fit.chi2 double nullable nh_min The 90% Lower Error on Intrinsic X-Ray Absorption H-atoms/cm^2 phys.columnDensity;stat.min double nullable spectral_index_neg_err The 90% Lower Error on X-Ray Photon Index stat.error;spect.index double nullable radio_loud_flag Radio-Loud Flag meta.code char nullable redshift Redshift src.redshift double nullable obs_sb_flux Observed-Frame Flux in 0.5-2 keV Band erg/s/cm^2 phot.flux;em.X-ray.soft double nullable bck_counts Background Counts; Scaled to Source Extraction Region ct phot;instr.background;em.X-ray double nullable exposure Live Exposure Time of X-Ray Observation (s) s time.duration;obs.exposure double nullable nh_gal Galactic Hydrogen Column Density in the Direction of the Source H-atoms/cm^2 phys.columnDensity double nullable nh_max The 90% Upper Error on Intrinsic X-Ray Absorption H-atoms/cm^2 phys.columnDensity;stat.max double nullable spectral_index_pos_err The 90% Upper Error on X-Ray Photon Index stat.error;spect.index double nullable dof Degrees of Freedom for Best-Fit Model stat.fit.dof short nullable off_axis Off-Axis Angle (arcmin) arcmin instr.offset double nullable obs_hb_flux Observed-Frame Flux in 2-10 keV Band erg/s/cm^2 phot.flux;em.X-ray.medium double nullable xray_fit_flag Flag Indicating Quality of the X-Ray Fit: -1=non-detection meta.code short nullable rest_frame_sb_flux Rest-Frame Flux in 0.5-2 keV Band erg/s/cm^2 phot.flux;em.X-ray.soft double nullable bal_flag Broad Absorption Line (BAL) Flag meta.code char nullable bii Galactic Latitude degree pos.galactic.lat double nullable nh Intrinsic X-Ray Absorption H-atoms/cm^2 phys.columnDensity double nullable lii Galactic Longitude degree pos.galactic.lon double nullable rest_frame_hb_flux Rest-Frame Flux in 2-10 keV Band erg/s/cm^2 phot.flux;em.X-ray.medium double nullable ox_spectral_index Optical-to-X-Ray Spectral Index spect.index;em.opt;em.X-ray double nullable