AGNSDSSXMM ivo://nasa.heasarc/agnsdssxmm NASA/GSFC HEASARC Akylas et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source 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 . 2006A&A...459..693A https://heasarc.gsfc.nasa.gov/W3Browse/all/agnsdssxmm.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=agnsdssxmm& GET text/xml 180 99999 true 358.456 -10.523 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=agnsdssxmm GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_agnsdssxmm&Action=More+Options&Action=Parameter+Search&ConeAdd=1 GALAXY CATALOG 0.0166666666666667 X-ray Optical public agnsdssxmm Sloan Digital Sky Survey/XMM-Newton AGN Spectral Properties Cata name Source Designation meta.id;meta.main char nullable ra Right Ascension degree pos.eq.ra;meta.main double nullable dec Declination degree pos.eq.dec;meta.main double nullable redshift Redshift src.redshift double nullable flux Intrinsic 2-8 keV Flux erg/s/cm^2 phot.flux;em.X-ray double nullable spectral_index Spectral Index spect.index;em.X-ray double nullable spectral_index_neg_err Error on Gamma (Lower Limit) stat.error;spect.index;em.X-ray double nullable spectral_index_pos_err Error on Gamma (Upper Limit) stat.error;spect.index;em.X-ray double nullable log_lx Logarithm of Intrinsic 2-8 keV Luminosity log(erg/s) phys.luminosity;em.X-ray 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 nh_limit Limit Flag on NH meta.code;phys.columnDensity char nullable lii Galactic Longitude degree pos.galactic.lon double nullable nh Observed Hydrogen Column Density, Best Fit Value H-atoms/cm^2 phys.columnDensity double nullable nh_gal Galactic Column Density in Directions of Observed Field H-atoms/cm^2 phys.columnDensity double nullable source_number Sequential Number meta.id short nullable nh_neg_err Error on NH (Lower Limit) H-atoms/cm^2 stat.error;phys.columnDensity double nullable opt_ctrprt_flag Flag for Optical Counterpart meta.code short nullable bii Galactic Latitude degree pos.galactic.lat double nullable int_rf_nh Intrinsic Rest Frame Column Density H-atoms/cm^2 phys.columnDensity double nullable nh_pos_err Error on NH (Upper Limit) H-atoms/cm^2 stat.error;phys.columnDensity double nullable