J/MNRAS/446/470ivo://CDS.VizieR/J/MNRAS/446/470doi:10.26093/cds/vizier.74460470CDSLuangtip W.Roberts T.P.Mineo S.Lehmer B.D.Alexander D.M.,Jackson F.E.Goulding A.D.Fischer J.L.2024-08-14T20:19:24Z2015-11-03T13:38:49ZCDS support team

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

cds-question@unistra.frgalaxiesinfrared-sourcesx-ray-sourcesWe present results from a Chandra study of ultraluminous X-ray sources (ULXs) in a sample of 17 nearby (D_L_<60Mpc) luminous infrared galaxies (LIRGs), selected to have star formation rates (SFRs) in excess of 7M_{sun}_/yr and low foreground Galactic column densities (N_H_<~5x10^20^cm^-2^). A total of 53 ULXs were detected and we confirm that this is a complete catalogue of ULXs for the LIRG sample. We examine the evolution of ULX spectra with luminosity in these galaxies by stacking the spectra of individual objects in three luminosity bins, finding a distinct change in spectral index at luminosity ~2x10^39^erg/s. This may be a change in spectrum as 10M_{sun}_ black holes transit from an ~ Eddington to a super-Eddington accretion regime, and is supported by a plausible detection of partially ionized absorption imprinted on the spectrum of the luminous ULX (L_X_~5x10^39^erg/s) CXOU J024238.9-000055 in NGC 1068, consistent with the highly ionized massive wind that we would expect to see driven by a super-Eddington accretion flow. This sample shows a large deficit in the number of ULXs detected per unit SFR (0.2 versus 2 ULXs, per M_{sun}_/yr) compared to the detection rate in nearby (D_L_<14.5Mpc) normal star-forming galaxies. This deficit also manifests itself as a lower differential X-ray luminosity function normalization for the LIRG sample than for samples of other star-forming galaxies. We show that it is unlikely that this deficit is a purely observational effect. Part of this deficit might be attributable to the high metallicity of the LIRGs impeding the production efficiency of ULXs and/or a lag between the star formation starting and the production of ULXs; however, we argue that the evidence - including very low N_ULX_/L_FIR_, and an even lower ULX incidence in the central regions of the LIRGs - shows that the main culprit for this deficit is likely to be the high column of gas and dust in these galaxies, that fuels the high SFR but also acts to obscure many ULXs from our view.2015MNRAS.446..470Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/446/470CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/452/739 : ULX sources and FIRST radio sources (Sanchez-Sutil+, 2006)J/ApJ/649/730 : ULX population in nearby galaxies from XMM (Winter+, 2006)J/ApJ/664/458 : Spectral fit of ULX sources (Devi+, 2007)J/ApJ/687/471 : Observational comparison between ULXs & XRBs (Berghea+, 2008)J/ApJ/741/49 : ULX candidates in nearby galaxies (Swartz+, 2011)J/AJ/143/144 : ULX candidates in nearby Arp galaxies (Smith+, 2012)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/446/470https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/446/470http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/446/470https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/446/470https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/446/470http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/446/470GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/446/470/tablea1 (ULX candidates detections, ordered by right ascension)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/446/470/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/446/470/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/446/470/tablea1?GETtext/xml+votable180.050000true2.4708325.930.005555555555555556Cone search capability for table J/MNRAS/446/470/tablea2 (Less luminous X-ray point sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/446/470/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/446/470/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/446/470/tablea2?GETtext/xml+votable180.050000true2.4708325.915280.0055555555555555566/5128 5130 6098 9133 10628 11180 17492 17754 20060 20254 26264 34531 43925 46399 46882https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/446/470?format=asciiX-rayInfrareddefaultJ/MNRAS/446/470/tablea1ULX candidates detections, ordered by right ascensionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000) of candidate ULXpos.eq.ra;meta.mainDEJ2000Declination (J2000) of candidate ULXpos.eq.dec;meta.mainHostHost galaxy namemeta.id.parentcharNetCtNet photon counts in 0.3-10keV energy bandctphot.count;em.X-rayfloatE_NetCtError on NetCt (upper value)ctstat.error;stat.maxfloate_NetCtError on NetCt (lower value)ctstat.errorfloatFluxSource flux in 0.3-10keV energy band1e-17W.m**-2phot.fluxfloatE_FluxError on Flux (upper value)1e-17W.m**-2stat.error;stat.maxfloate_FluxError on Flux (lower value)1e-17W.m**-2stat.error;phot.fluxfloatLumSource luminosity, assuming the source is at the distance of the host galaxy1e+32Wphys.luminosityfloatE_LumError on Lum (upper value)1e+32Wstat.error;stat.maxfloate_LumError on Lum (lower value)1e+32Wstat.errorfloatNotes? Notes (1)meta.noteintnullableJ/MNRAS/446/470/tablea2Less luminous X-ray point sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000) of candidate ULXpos.eq.ra;meta.mainDEJ2000Declination (J2000) of candidate ULXpos.eq.dec;meta.mainHostHost galaxy namemeta.id.parentcharNetCtNet photon counts in 0.3-10keV energy bandctphot.count;em.X-rayfloatE_NetCtError on NetCt (upper value)ctstat.error;stat.maxfloate_NetCtError on NetCt (lower value)ctstat.errorfloatFluxSource flux in 0.3-10keV energy band1e-17W.m**-2phot.fluxfloatE_FluxError on Flux (upper value)1e-17W.m**-2stat.error;stat.maxfloate_FluxError on Flux (lower value)1e-17W.m**-2stat.error;phot.fluxfloatLumSource luminosity, assuming the source is at the distance of the host galaxy1e+32Wphys.luminosityfloatE_LumError on Lum (upper value)1e+32Wstat.error;stat.maxfloate_LumError on Lum (lower value)1e+32Wstat.errorfloatNotes? Notes (1)meta.noteintnullable