J/MNRAS/537/1444ivo://CDS.VizieR/J/MNRAS/537/1444doi:10.26093/cds/vizier.75371444CDSBelvedersky M.I.Bykov S.D.Gilfanov M.R.Medvedev P.S.Sunyaev R.A.2025-03-03T20:14:38Z2025-02-06T12:49:21ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleix-ray-sourcesWe search for reflection-dominated Compton-thick active galactic nuclei (CT AGN) candidates in the Lockman Hole region using the data of SRG/eROSITA Lockman Hole survey. We selected sources with anomalously hard photon indices in the 0.3-8.0keV band, untypical for type I AGN. In particular, we required that the upper end of the 9% error interval did not exceed a fiducial boundary of GAMMA=1.3. We found 291 sources which constitute a rare subpopulation among extragalactic X-ray sources detected by eROSITA in the Lockman Hole field, ~5%. These sources constitute the eROSITA sample of CT AGN candidates in the Lockman Hole field. We further divide the sources into three categories depending on the availability of reliable redshift and statistically significant detection of intrinsic absorption. We present two catalogues: the bright sample (37 sources) and the faint one (254). We estimate the fraction and sky density of reflection-dominated CT AGN candidates. We show examples of individual spectra and use stacking analysis to search for possible redshift evolution of their properties with redshift. We analyse combined eROSITA spectra of bright sources of different categories with a physically motivated spectral model UXCLUMPY and find them fully consistent with the fits to the ~1Msec XMM-Newton data for one of our reflection-dominated CT candidate, Type 2 galaxy SRGe J105348.6+573032. The catalogues of CT AGN candidates could be a good starting point for planning future studies and follow-ups at all wavelengths.2025MNRAS.537.1444Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/537/1444CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/537/1444https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/537/1444http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/537/1444https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/537/1444https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/537/1444http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/537/1444GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/537/1444/tablea1 (SRG/eROSITA CT AGN candidates in Lockman Hole, bright sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/537/1444/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/537/1444/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/537/1444/tablea1?GETtext/xml+votable180.050000true160.283723674380556.33317120985570.005555555555555556Cone search capability for table J/MNRAS/537/1444/tablea2 (SRG/eROSITA CT AGN candidates in Lockman Hole, faint sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/537/1444/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/537/1444/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/537/1444/tablea2?GETtext/xml+votable180.050000true158.778480022528856.48022088176890.0055555555555555564/379 5/1528 1861 6/6038 6041 6043-6044 6046-6047 6061 6063 6088 6090-6091 6120 6122 7441https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/537/1444?format=asciiX-raydefaultJ/MNRAS/537/1444/tablea1SRG/eROSITA CT AGN candidates in Lockman Hole, bright samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintsrcidSRG/eROSITA short unique source ID (srcid)meta.idintNameSRG/eROSITA source name, SRGe JHHMMSS.s+DDMMSS (NAME)meta.id;meta.maincharRAJ2000SRG/eROSITA right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000SRG/eROSITA declination (J2000) (DEC)degpos.eq.dec;meta.mainePosSRG/eROSITA positional uncertainty (98% confidence) (POS_R98)arcsecstat.error;stat.fit.paramdoubleCtsSRG/eROSITA source count number (CTS)ctphot.count;em.X-raydoublee_Cts? SRG/eROSITA source count number error (CTS_ERR)ctstat.errordoublenullablezRedshift (z)src.redshiftdoubleF0.5-2.0SRG/eROSITA source flux in the 0.5-2.0keV energy range (FLUX_05-20)1e-17W.m**-2phot.flux;em.X-raydoublee_F0.5-2.0? SRG/eROSITA source flux error in the 0.5-2.0keV energy range (FLUX_05-20_ERR)1e-17W.m**-2stat.errordoublenullableCat[1/3] Category of a reflection-dominated CT AGN candidate (category) (1)meta.codeintDESIOptical counterpart ID from Bykov et al. (2022, AstL, 48, 653, doi.org/10.1134/S1063773722110044) (desi_id)meta.id;spect.dopplerVeloc.optcharRADdegOptical counterpart right ascension (J2000) (desi_ra)degpos.eq.raDEDdegOptical counterpart declination (J2000) (desi_dec)degpos.eq.decmo1-PhIndex? Photon index derived using the phabs*powerlaw XSPEC model (model 1) (mo1_PhoIndex)spect.indexfloatnullableE_mo1-PhIndex? Photon index positive error (90% confidence, model 1) (mo1_PhoIndex_perr)stat.error;stat.maxfloatnullablee_mo1-PhIndex[] Photon index negative error (90% confidence, model 1) (mo1_PhoIndex_nerr)stat.errorfloatmo2-PhIndex? Photon index derived using the phabs*zphabs*zpowerlw XSPEC model (model 2) (mo2_PhoIndex)spect.indexfloatnullableE_mo2-PhIndex? Photon index positive error (90% confidence, model 2) (mo2_PhoIndex_perr)stat.error;stat.maxdoublenullablee_mo2-PhIndex? Photon index negative error (90% confidence, model 2) (mo2_PhoIndex_nerr)stat.errordoublenullablemo2-nH? Intrinsic absorption derived using the phabs*zphabs*zpowerlw XSPEC model (model 2) (mo2_nH)1e-22cm**-2phys.columnDensitydoublenullableE_mo2-nH? Intrinsic absorption positive error (90% confidence, model 2) (mo2_nH_perr)1e-22cm**-2stat.error;stat.maxdoublenullablee_mo2-nH? Intrinsic absorption negative error (90% confidence, model 2) (mo2_nH_nerr)1e-22cm**-2stat.errordoublenullablen_z[ps] spectroscopic (s) or photometric (p) redshift (is_z_spec)meta.notecharJ/MNRAS/537/1444/tablea2SRG/eROSITA CT AGN candidates in Lockman Hole, faint sampleRAJ2000SRG/eROSITA right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000SRG/eROSITA declination (J2000) (DEC)degpos.eq.dec;meta.mainePosSRG/eROSITA positional uncertainty (98% confidence) (POS_R98)arcsecstat.error;stat.fit.paramdoubleCtsSRG/eROSITA source count number (CTS)ctphot.count;em.X-raydoublee_Cts? SRG/eROSITA source count number error (CTS_ERR)ctstat.errordoublenullableCat[1/3] Category of a reflection-dominated CT AGN candidate (category) (1)meta.codeintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintsrcidSRG/eROSITA short unique source ID (srcid)meta.idintNameSRG/eROSITA source name, SRGe JHHMMSS.s+DDMMSS (NAME)meta.id;meta.maincharF0.5-2.0SRG/eROSITA source flux in the 0.5-2.0keV energy range (FLUX_05-20)1e-17W.m**-2phot.flux;em.X-raydoublee_F0.5-2.0? SRG/eROSITA source flux error in the 0.5-2.0keV energy range (FLUX_05-20_ERR)1e-17W.m**-2stat.errordoublenullableDESIOptical counterpart ID from Bykov et al. (2022, AstL, 48, 653, doi.org/10.1134/S1063773722110044) (desi_id)meta.id;spect.dopplerVeloc.optcharRADdegOptical counterpart right ascension (J2000) (desi_ra)degpos.eq.raDEDdegOptical counterpart declination (J2000) (desi_dec)degpos.eq.decmo1-PhIndex? Photon index derived using the phabs*powerlaw XSPEC model (model 1) (mo1_PhoIndex)spect.indexfloatnullableE_mo1-PhIndex? Photon index positive error (90% confidence, model 1) (mo1_PhoIndex_perr)stat.error;stat.maxfloatnullablee_mo1-PhIndex[] Photon index negative error (90% confidence, model 1) (mo1_PhoIndex_nerr)stat.errorfloatmo2-PhIndex? Photon index derived using the phabs*zphabs*zpowerlw XSPEC model (model 2) (mo2_PhoIndex)spect.indexfloatnullableE_mo2-PhIndex? Photon index positive error (90% confidence, model 2) (mo2_PhoIndex_perr)stat.error;stat.maxdoublenullablee_mo2-PhIndex? Photon index negative error (90% confidence, model 2) (mo2_PhoIndex_nerr)stat.errordoublenullablemo2-nH? Intrinsic absorption derived using the phabs*zphabs*zpowerlw XSPEC model (model 2) (mo2_nH)1e-22cm**-2phys.columnDensitydoublenullableE_mo2-nH? Intrinsic absorption positive error (90% confidence, model 2) (mo2_nH_perr)1e-22cm**-2stat.error;stat.maxdoublenullablee_mo2-nH? Intrinsic absorption negative error (90% confidence, model 2) (mo2_nH_nerr)1e-22cm**-2stat.errordoublenullablezRedshift (z)src.redshiftdoublen_z[ps] spectroscopic (s) or photometric (p) redshift (is_z_spec)meta.notechar