J/MNRAS/471/364ivo://CDS.VizieR/J/MNRAS/471/364doi:10.26093/cds/vizier.74710364CDSBaronchelli L.Koss M.Schawinski K.Cardamone C.Civano F.,Comastri A.Elvis M.Lanzuisi G.Marchesi S.Ricci C.Salvato M.,Trakhtenbrot B.Treister E.2024-08-17T20:20:29Z2020-07-03T14:27:26ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.fractive-galactic-nucleiredshiftedx-ray-sourcesTo fully understand cosmic black hole growth, we need to constrain the population of heavily obscured active galactic nuclei (AGNs) at the peak of cosmic black hole growth (z~1-3). Sources with obscuring column densities higher than 10^24^atoms/cm^2^, called Compton-thick (CT) AGNs, can be identified by excess X-ray emission at ~20-30keV, called the 'Compton hump'. We apply the recently developed Spectral Curvature (SC) method to high-redshift AGNs (2<z<5) detected with Chandra. This method parametrizes the characteristic 'Compton hump' feature cosmologically redshifted into the X-ray band at observed energies <10 keV. We find good agreement in CT AGNs found using the SC method, and bright sources fit using their full spectrum with X-ray spectroscopy. In the Chandra Deep Field-South, we measure a CT fraction of 17^+19^_-11_% (3/17) for sources with observed luminosity >5x10^43^erg/s. In the Cosmological Evolution Survey (COSMOS), we find an observed CT fraction of 15^+4^_-3_% (40/272) or 32+/-11 per cent when corrected for the survey sensitivity. When comparing to low redshift AGNs with similar X-ray luminosities, our results imply that the CT AGN fraction is consistent with having no redshift evolution. Finally, we provide SC equations that can be used to find high-redshift CT AGNs (z>1) for current (XMM-Newton) and future (eROSITA and ATHENA) X-ray missions.2017MNRAS.471..364Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/471/364CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/817/34 : C-COSMOS Legacy sources multiwavelength catalog (Marchesi+ 2016)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/471/364https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/471/364http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/471/364https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/471/364https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/471/364http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/471/364GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/471/364/table2 (Spectral curvature values for the analysed in the COSMOS legacy survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/471/364/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/471/364/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/471/364/table2?GETtext/xml+votable180.050000true150.58770832.77316670.0055555555555555565/6814 6/27245 27247 27344https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/471/364?format=asciiX-raydefaultJ/MNRAS/471/364/table2Spectral curvature values for the analysed in the COSMOS legacy surveySimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDIdentification number of the source, from the COSMOS legacy survey (Marchesi et al. 2016, Cat. J/ApJ/817/34)meta.numbercharzSpectroscopic redshift from Marchesi et al. (2016, Cat. J/ApJ/817/34)src.redshiftfloatsoftNumber of counts in the soft energy range [8-12]/(1+z)keVctphot.count;em.X-rayinte_softrms uncertainty on softctstat.errorintmidNumber of counts in the mid energy range [12-16]/(1+z)keVctphot.count;em.X-rayinte_midrms uncertainty on softctstat.errorinthardNumber of counts in the hard energy range [16-24]/(1+z)keVctphot.count;em.X-rayinte_hardrms uncertainty on softctstat.errorinttotNumber of counts in the total energy range [8-24]/(1+z)keVctphot.count;em.X-rayinte_totrms uncertainty on softctstat.errorintSCMeasured Spectral Curvature valuesspect.indexfloate_SCrms uncertainty on SCstat.errorfloatNH1? Column density from Marchesi et al. (2016, Cat. J/ApJ/817/34) estimated using a hardness ratio (10^22^atom/cm^2^)1e+22cm**-2phys.columnDensityfloatnullableNH2? Column density estimated from Marchesi et al. (2016ApJ...830..100M) spectral fitting (10^22^atom/cm^2^)1e+22cm**-2phys.columnDensityfloatnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main