CHAMP (Chandra Multiwavelength Project) Hard X-Ray Emitting AGN

CHAMP (Chandra Multiwavelength Project) Hard X-Ray Emitting AGN CHAMPHXAGN ivo://nasa.heasarc/champhxagn NASA/GSFC HEASARC Silverman et al. 2026-10-09 NASA/GSFC HEASARC help desk heasarc-vo at athena.gsfc.nasa.gov Survey Source This table contains the results from an X-ray and optical analysis of 188 active galactic nuclei (AGN) identified from 497 hard X-ray (observed flux in the (2.0 - 8.0 keV) band > 2.7 x 10-15 erg/cm2/s) sources in 20 Chandra fields (1.5 square degrees) forming part of the Chandra Multiwavelength Project (ChaMP). These medium-depth X-ray observations enable the detection of a representative subset of those sources responsible for the bulk of the 2 - 8 keV cosmic X-ray background. Brighter than the survey's optical spectroscopic limit, the authors achieve a reasonable degree of completeness (77% of X-ray sources with counterparts r' < 22.5 have been classified): broad emission-line AGNs (62%), narrow emission-line galaxies (24%), absorption-line galaxies (7%), stars (5%), or clusters (2%). To construct a pure AGN sample, the authors required the rest-frame 2.0-8.0 keV luminosity (uncorrected for intrinsic absorption) to exceed 1042 erg s-1, thereby excluding any sources that may contain a significant stellar or hot ISM component. The most luminous known star-forming or elliptical galaxies attain at most LX = 1042 erg s-1. Since many of the traditional optical AGN signatures are not present in obscured sources, high X-ray luminosity becomes the authors' single discriminant for supermassive black hole accretion. They believe that almost all of the NELGs and ALGs harbor accreting SMBHs based on their X-ray luminosity. They find that 90% of the identified ChaMP sources have luminosities above this threshold. These selection criteria yield a sample of 188 AGNs from 20 Chandra fields with f(2-8 keV) > 2.7 x 10-15 erg cm-2 s-1, r' < 22.5, and LX > 1042 erg s-1. The authors removed five objects identified as clusters based on their extended X-ray emission. This table was created by the HEASARC in March 2007 based on the CDS table J/ApJ/618/123, file table4.dat. This is a service provided by NASA HEASARC . 2005ApJ...618..123S https://heasarc.gsfc.nasa.gov/W3Browse/all/champhxagn.html Catalog Research served-by HEASARC TAP https://heasarc.gsfc.nasa.gov/xamin/vo/cone?showoffsets&table=champhxagn& GET text/xml 180 99999 true 85.69008333 -41.10194444 0.0166666666666667 https://heasarc.gsfc.nasa.gov/xamin/vo/tap https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/getvotable.pl?name=champhxagn GET text/xml https://heasarc.gsfc.nasa.gov/cgi-bin/W3Browse/w3query.pl?tablehead=name=heasarc_champhxagn&Action=More+Options&Action=Parameter+Search&ConeAdd=1 CHANDRA 0.0166666666666667 Optical X-ray public champhxagn CHAMP (Chandra Multiwavelength Project) Hard X-Ray Emitting AGN name ChaMP Object 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 counts Counts in the 2-8keV Band ct phot;em.X-ray.medium double nullable counts_error Uncertainty in the Counts ct stat.error;phot;em.X-ray.medium double nullable redshift Redshift src.redshift double nullable log_lx Logarithm of the Rest Frame 2-8keV Luminosity (in erg/s) log(erg/s) double nullable rmag SDSS r Filter Magnitude mag phot.mag;em.opt.R double nullable hardness_ratio Hardness Ratio phot.flux;arith.ratio;em.X-ray.medium double nullable hardness_ratio_limit Limit Flag for Hardness Ratio char nullable broad_type Broad Object Classification char nullable log_nh_limit Limit Flag for Log_NH char nullable gi_color_limit Limit Flag for g-i Color char nullable class Browse Object Classification src.class short nullable ri_color_limit Limit Flag for r-i char nullable bii Galactic Latitude degree pos.galactic.lat double nullable source_flag Flag [e] Indicates Source Near the Chip Gap, No Spectral Fitting Performed char nullable log_nh_neg_err Lower Limit of Log_NH log(H-atoms/cm^2) double nullable log_nh Logarithm of the Hydrogen Column Density log(H-atoms/cm^2) double nullable lii Galactic Longitude degree pos.galactic.lon double nullable flux Galactic Absorption-Corrected 2-8keV Flux (erg/s/cm^2) erg/s/cm^2 phot.flux;em.X-ray.medium double nullable gi_color SDSS g-i Color mag double nullable source_number Sequential Identification Number for Each X-Ray Source in Catalog meta.id short nullable ri_color SDSS r-i Color mag double nullable log_nh_pos_err Upper Limit of Log_NH log(H-atoms/cm^2) 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