J/AcA/69/339ivo://CDS.VizieR/J/AcA/69/339doi:10.26093/cds/vizier.120690339CDSSingha A.C.Devi A.S.2025-09-25T20:16:35Z2023-06-19T12:07:58ZCDS support team

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

cds-question@unistra.frgalaxiesx-ray-binary-stars163 X-ray point sources having luminosities in excess of 10^38^erg/s within the energy range 0.3-10.0keV are identified in a sample of 50 galaxies observed by Chandra ACIS-S. 18 sources are found to have a total (time integrated) background flux greater than 2 cts/arcsec^2^ and hence excluded from the analysis to avoid any possible background/foreground contamination. The spectra of the remaining 145 sources are fitted using two spectral models - an absorbed power law and an absorbed disk blackbody. We report the discovery of four hyperluminous X-ray source candidates (X-ray luminosity: LX>10^41^erg/s) - Src1, Src2, Src3 and Src22. In this study, a total of 17 hyperluminous X-ray sources were identified. The spectra of 13 sources were found to be equally represented by both the models except for three sources preferring the power law model and one source preferring the disk blackbody model. It is found that the spectra of seven hyperluminous X-ray sources are in the soft state with their inner disk temperature (kTin) lying in the range of 0.19-0.56keV (or power law photon index, {Gamma}>3) and the remaining 10 hyperluminous X-ray sources are in hard state with kTin around 1.0-2.0keV (or power law photon index, {Gamma}~=1.6). This shows a clear bimodal distribution of the high luminosity X-ray sources and hence they can be grouped into two distinct spectral classes. From the disk blackbody model, the black hole masses of the soft hyperluminous X-ray sources are estimated (assuming the inner disk radius, R_in_~=10GM/c^2^) to be within ~=10^3^-10^4^M_{sun}_. Also considering an anisotropic emission, for maximum beaming ({eta}=5) with no color correction, the estimated black hole masses lie within ~=10^2^-10^3^M_{sun}_ , which is in the intermediate mass black hole range.2019AcA....69..339Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AcA/69/339CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AcA/69/339https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AcA/69/339http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AcA/69/339https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AcA/69/339https://vizier.iucaa.in/viz-bin/votable?-source=J/AcA/69/339http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AcA/69/339GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AcA/69/339/table1 (Chandra ACIS-S galaxy observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AcA/69/339/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AcA/69/339/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AcA/69/339/table1?GETtext/xml+votable180.050000true16.853173913.53592440.005555555555555556Cone search capability for table J/AcA/69/339/table2 (Properties of the X-ray point sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AcA/69/339/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/AcA/69/339/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AcA/69/339/table2?GETtext/xml+votable180.050000true16.840041713.52253890.0055555555555555566/2359 2409 3506 5075 6034 6040 6098 7606 7799 7997 8173 8203 8225 9468 9583 10379 10991 11432 11434 11512 12025 13401 15592-15593 16713 17428-17429 18209 18367 20000 22396 26265 27515 27713 27719 27735 27907 28167 28275 31158 33193 34471 34535 35055 35548 35565 35576 36785 38139 43339 43420 43898 45305 46811https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AcA/69/339?format=asciiX-raydefaultJ/AcA/69/339/table1Chandra ACIS-S galaxy observationsSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget namemeta.id;meta.maincharObsIDObservation IDmeta.id;obsintObs.dateObservation datetime.epoch;obsnullableTexpExposure timekstime.duration;obs.exposurefloatDistDistanceMpcpos.distancefloatRefReferencemeta.ref;pos.framechar_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.mainJ/AcA/69/339/table2Properties of the X-ray point sourcesSourceSource Number (SrcNNN)meta.id;meta.maincharn_Source[* ] Note on Source (1)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTargetTarget galaxy namemeta.idcharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainCountsCountsctphot.count;em.X-rayintBkgCountsBackground Countsctinstr.backgroundintJ/AcA/69/339/table3Spectral properties of the pile-up corrected sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintE_kTinDBDisk blackbody kT_in_ temperature upper errorkeVstat.error;stat.maxfloatNHPLPower law Hydrogen column density1e+22cm**-2phys.columnDensityfloatPufPLPower law pile-up fractionstat.fit.paramfloatGAMMAPLPower law photon index GAMMAspect.indexfloatE_GAMMAPLPower law photon index GAMMA upper errorstat.error;stat.maxfloate_kTinDBDisk blackbody kT_in_ temperature lower errorkeVstat.errorfloatlogLDBDisk blackbody luminositylog(1e-07W)phys.luminosity;em.X-rayfloate_GAMMAPLPower law photon index GAMMA lower errorstat.errorfloatlogLPLPower law luminositylog(1e-07W)phys.luminosity;em.X-rayfloatE_logLPLPower law luminosity upper errorlog(1e-07W)stat.error;stat.maxfloate_logLPLPower law luminosity lower errorlog(1e-07W)stat.errorfloatrchi2PLPower law reduced chi2stat.fit.chi2floatPufDBPile-up fraction Disk blackbodystat.fit.paramfloatkTinDBDisk blackbody kT_in_ temperaturekeVphys.temperaturefloatE_logLDBDisk blackbody luminosity upper errorlog(1e-07W)stat.error;stat.maxfloate_logLDBDisk blackbody luminosity lower errorlog(1e-07W)stat.errorfloatrchi2DBReduced chi Disk blackbody2stat.fit.chi2floatSourceSource number (SrcNNN)meta.id;meta.maincharJ/AcA/69/339/table4Spectral properties of the point sourcesrC-statPLPower-law reduced C-statstat.fit.goodnessfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSourceSource Number (SrcNNN)meta.id;meta.maincharn_Source[*] Note on source (1)meta.notecharNHPLPower-law Hydrogen column density1e+22cm**-2phys.columnDensityfloatE_NHPLPower-law Hydrogen column density upper error1e+22cm**-2stat.error;stat.maxfloate_NHPLPower-law Hydrogen column density lower error1e+22cm**-2stat.errorfloatGAMMAPLPower-law photon index GAMMAspect.indexfloatE_GAMMAPLPower-law photon index GAMMA upper errorstat.error;stat.maxfloate_GAMMAPLPower-law photon index GAMMA lower errorstat.errorfloatlogLPLPower-law luminositylog(1e-07W)phys.luminosity;em.X-rayfloatE_logLPLPower-law luminosity upper errorlog(1e-07W)stat.error;stat.maxfloate_logLPLPower-law luminosity lower errorlog(1e-07W)stat.errorfloatNHDBDisk blackbody Hydrogen column density1e+22cm**-2phys.columnDensityfloatE_NHDBDisk blackbody Hydrogen column density upper error1e+22cm**-2stat.error;stat.maxfloate_NHDBDisk blackbody Hydrogen column density lower error1e+22cm**-2stat.errorfloatkTinDBDisk blackbodykeVphys.temperaturefloatE_kTinDBDisk blackbody upper errorkeVstat.error;stat.maxfloate_kTinDBDisk blackbody lower errorkeVstat.errorfloatlogLDBDisk blackbody luminositylog(1e-07W)phys.luminosity;em.X-rayfloatE_logLDBDisk blackbody luminosity upper errorlog(1e-07W)stat.error;stat.maxfloate_logLDBDisk blackbody luminosity lower errorlog(1e-07W)stat.errorfloatrC-statDBDisk blackbody reduced C-statstat.fit.goodnessfloat