J/ApJ/721/1368ivo://CDS.VizieR/J/ApJ/721/1368doi:10.26093/cds/vizier.17211368CDSLi Z.Spitler L.R.Jones C.Forman W.R.Kraft R.P.Stefano R.D.,Tang S.Wang Q.D.Gilfanov M.Revnivtsev M.2018-01-30T07:18:08Z2012-08-29T07:57:14ZCDS support team

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

cds-question@unistra.frglobular-star-clustersgalaxiesx-ray-sourcesWe present a study of discrete X-ray sources in and around the bulge-dominated, massive Sa galaxy, Sombrero (M104), based on new and archival Chandra observations with a total exposure of ~200ks. With a detection limit of L_X_~10^37^erg/s and a field of view covering a galactocentric radius of ~30kpc (11.5'), 383 sources are detected. Cross-correlation with Spitler et al.'s catalog of Sombrero globular clusters (GCs) (Cat. J/AJ/132/1593) identified from HST/ACS observations reveals 41 X-ray sources in GCs, presumably low-mass X-ray binaries (LMXBs). We quantify the differential luminosity functions (LFs) for both the detected GC and field LMXBs, whose power-law indices (~1.1 for the GC-LF and ~1.6 for field-LF) are consistent with previous studies for elliptical galaxies. With precise sky positions of the GCs without a detected X-ray source, we further quantify, through a fluctuation analysis, the GC-LF at fainter luminosities down to 10^35^erg/s. We also detect 101 sources in the halo of Sombrero. The presence of these sources cannot be interpreted as galactic LMXBs whose spatial distribution empirically follows the starlight. Their number is also higher than the expected number of cosmic active galactic nuclei (52+/-11 [1{sigma}]) whose surface density is constrained by deep X-ray surveys.2010ApJ...721.1368Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/721/1368CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/401/1965 : Globular clusters in M104 (Harris+, 2010)J/MNRAS/389/1150 : Spitzer photometry of GCs in 2 galaxies (Spitler+, 208)J/ApJ/658/980 : New velocities for 62 GCs in M104 (Bridges+, 2007)J/MNRAS/376/960 : X-ray in the Sombrero galaxy (NGC 4594) (Li+, 2007)J/ApJ/662/525 : LMXBs in globular clusters of 5 galaxies (Kundu+, 2007)J/AJ/132/1593 : BVR photometry of NGC 4594 GCs (Spitler+, 2006)J/ApJ/599/1067 : X-ray sources in M104 (Di Stefano+, 2003)J/MNRAS/327/1116 : VI photometry of Sombrero globular clusters (Larsen+, 2001)J/ApJ/458/455 : M 104 planetary nebulae (Ford+ 1996)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/721/1368https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/721/1368http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/721/1368https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/721/1368https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/721/1368http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/721/1368GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/721/1368/table1 (Chandra source list)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/721/1368/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/721/1368/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/721/1368/table1?GETtext/xml+votable180.050000true189.83175-11.53747220.005555555555555556Cone search capability for table J/ApJ/721/1368/Xobs (List of sources detected from ObsIDs 1586 (table2), 9532 (table3) and 9533 (table4))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/721/1368/Xobs?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/721/1368/Xobs?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/721/1368/Xobs?GETtext/xml+votable180.050000true189.8316667-11.53786110.005555555555555556Cone search capability for table J/ApJ/721/1368/table5 (List of X-ray sources associated with Sombrero globular clusters (most likely LMXBs))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/721/1368/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/721/1368/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/721/1368/table5?GETtext/xml+votable180.050000true189.83178-11.537490.0055555555555555566/250832.762881831355591e-19 4.920466254354166e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/721/1368?format=asciiX-raydefaultJ/ApJ/721/1368/table1Chandra source listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/383] Generic source number (not as in other tables)meta.id;meta.mainintglSource associated with a globular cluster (table5)meta.ref.urlintnullableCXOUCXOU source name (JHHMMSS.ss+DDMMSS.s) (G1)meta.id;meta.mainchare_pos[0/2.4] The 1{sigma} positional uncertainty (1)arcsecstat.errorfloatCROn-axis source F-band count rate (0.4-6keV) (G2)ct/sphot.count;em.X-rayfloate_CRUncertainty in CRct/sstat.errorfloatCR1The 0.4-0.7keV band count rate (S1)ct/sphot.count;em.X-rayfloate_CR1Uncertainty in CR1ct/sstat.errorfloatCR2The 0.7-1keV band count rate (S2)ct/sphot.count;em.X-rayfloate_CR2Uncertainty in CR2ct/sstat.errorfloatCR3The 1-2keV band count rate (H1)ct/sphot.count;em.X-rayfloate_CR3Uncertainty in CR3ct/sstat.errorfloatCR4The 2-6keV band count rate (H2)ct/sphot.count;em.X-rayfloate_CR4Uncertainty in CR4ct/sstat.errorfloatHRHardness ratio (H2-M-S1)/(H2+M+S1) (G3)phot.flux;arith.ratiofloate_HRUncertainty in HRstat.errorfloatHR1Hardness ratio (M-S1)/(M+S1) (G3)phot.flux;arith.ratiofloate_HR1Uncertainty in HR1stat.errorfloatHR2Hardness ratio (H2-H1)/(H2+H1) (G3)phot.flux;arith.ratiofloate_HR2Uncertainty in HR2stat.errorfloatFlagBand(s) in which a source is detected (G3)meta.code.errorcharS06Cross-match with Spitler et al. catalogs within 1.5"meta.ref.urlintnullableAllDisplay data from all tables of this paper for this objectmeta.ref.urlchar_RAPositions from CXOU name (right ascension part)degpos.eq.ra;meta.main_DEPositions from CXOU name (declination part)degpos.eq.dec;meta.mainJ/ApJ/721/1368/XobsList of sources detected from ObsIDs 1586 (table2), 9532 (table3) and 9533 (table4)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObsIDChandra observation IDmeta.id;obsintnullableSeq[1/329] Generic source number within the tablemeta.id;meta.mainintCXOUCXOU source name (JHHMMSS.ss+DDMMSS.s) (G1)meta.id;meta.maincharCROn-axis source F-band count rate (G2)ct/sphot.count;em.X-rayfloate_CRUncertainty in CRct/sstat.errorfloatCR1The 0.4-0.7keV band count rate (S1)ct/sphot.count;em.X-rayfloate_CR1Uncertainty in CR1ct/sstat.errorfloatCR2The 0.7-1keV band count rate (S2)ct/sphot.count;em.X-rayfloate_CR2Uncertainty in CR2ct/sstat.errorfloatCR3The 1-2keV band count rate (H1)ct/sphot.count;em.X-rayfloate_CR3Uncertainty in CR3ct/sstat.errorfloatCR4The 2-6keV band count rate (H2)ct/sphot.count;em.X-rayfloate_CR4Uncertainty in CR4ct/sstat.errorfloatFlagBand(s) in which a source is detected (G3)meta.code.errorcharAllDisplay data from all tables of this paper for this objectmeta.ref.urlchar_RAPositions from CXOU name (right ascension part)degpos.eq.ra;meta.main_DEPositions from CXOU name (declination part)degpos.eq.dec;meta.mainJ/ApJ/721/1368/table5List of X-ray sources associated with Sombrero globular clusters (most likely LMXBs)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[46/346] Generic X-ray source number (as in table 1)meta.id;meta.mainintRAJ2000Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainBmagB-band apparent magnitudemagphot.mag;em.opt.BfloatVmagV-band apparent magnitudemagphot.mag;em.opt.VfloatRmagR-band apparent magnitudemagphot.mag;em.opt.RfloatFx0.3-8keV intrinsic flux in 10^-14^erg/szWphot.flux;em.X-rayfloatAllDisplay data from all tables of this paper for this objectmeta.ref.urlchar