J/ApJ/947/31ivo://CDS.VizieR/J/ApJ/947/31doi:10.26093/cds/vizier/ba-xk-zCDSHunt Q.Gallo E.Chandar R.Mok A.Prestwich A.2026-07-02T11:59:02Z2025-05-14T14:11:12ZCDS support team

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

cds-question@unistra.frx-ray-binary-starshst-photometryvisible-astronomytwo-color-diagramsWe characterize the optical counterparts to the compact X-ray source population within the nearby spiral galaxy M81 using multiband Hubble Space Telescope (HST) imaging data. By comparing the optical luminosities and colors measured for candidate donor stars and host clusters to stellar and cluster evolutionary models, respectively, we estimate the likely masses and upper age limits of the field and cluster X-ray binaries. We identify 15 low-mass X-ray binaries (i.e., donor star mass <~3M_{sun}_) within ancient globular clusters, as well as 42 candidate high-mass X-ray binaries (i.e., donor star mass >~8M_{sun}_). To estimate the likelihood of misclassifications, we inject 4000 artificial sources into the HST mosaic image and conclude that our classifications of globular clusters and high-mass X-ray binaries are reliable at the >90% level. We find that globular clusters that host X-ray binaries are on average more massive and more compact than globular clusters that do not. However, there is no apparent correlation between the X-ray brightness of the clusters and their masses or densities, nor are X-ray binary hosts more X-ray luminous than the general field population of low-mass X-ray binaries. This work represents one of the first in-depth analyses of the population of X-ray binaries within globular clusters in a spiral galaxy.2023ApJ...947...31Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/947/31CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)B/chandra : The Chandra Archive Log (CXC, 1999-2014)IX/57 : The Chandra Source Catalog (CSC), Release 2.0 (Evans+, 2019)J/ApJ/595/685 : HST imaging in Chandra Deep Field-South (Grogin+, 2003)J/ApJ/613/279 : ACS Virgo Cluster Survey. III. M87 (Jordan+, 2004)J/ApJS/150/19 : ChaMP. I. First X-ray source catalog (Kim+, 2004)J/ApJS/169/401 : ChaMP X-ray point source catalog (Kim+, 2007)J/ApJ/662/525 : LMXBs in globular clusters of 5 galaxies (Kundu+, 2007)J/ApJ/689/983 : LMXBs in early-type galaxies. I. Chandra (Humphrey+, 2008)J/ApJ/714/25 : AMUSE-Virgo survey. II. (Gallo+, 2010)J/AJ/139/2620 : Spectroscopy of M81 globular clusters (Nantais+, 2010)J/AJ/139/1413 : M81 star cluster candidates (Nantais+, 2010)J/MNRAS/405/1293 : Compact star clusters in M81 (Santiago-Cortes+, 2010)J/AJ/142/183 : HST photometry of globulars in M81 (NGC 3031) (Nantais+, 2011)J/ApJ/754/67 : Longslit spectroscopy of local bulges (Fabricius+, 2012)J/MNRAS/419/2095 : HMXBs in nearby galaxies (Mineo+, 2012)J/ApJS/212/21 : A deep Chandra ACIS survey of M83 (Long+, 2014)J/ApJ/862/73 : Deep Chandra obs. of X-ray point sources in M87 (Luan+, 2018)J/ApJS/243/3 : Chandra observations of SINGS galaxies (Lehmer+, 2019)J/ApJ/890/150 : X-ray binaries in M101 with HST optical data (Chandar+, 2020)J/ApJS/248/31 : HST & Chandra obs. of elliptical galaxies (Lehmer+, 2020)J/ApJ/912/31 : M83 X-ray binary classifications from HST (Hunt+, 2021)J/MNRAS/509/180 : GC in 5 nearby spiral galaxies (Lomeli-Nunez+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/947/31https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/947/31http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/947/31https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/947/31https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/947/31http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/947/31GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/947/31/table3 (Properties and classifications of M81 X-ray sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/947/31/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/947/31/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/947/31/table3?GETtext/xml+votable180.050000true148.57923569.069508060.0055555555555555566/7606https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/947/31?format=asciiX-rayOpticaldefaultJ/ApJ/947/31/table3Properties and classifications of M81 X-ray sourcesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDLehmer+ 2019, J/ApJS/243/3 identifier (<[LET2019] NGC 3031 NNN> in Simbad)meta.id;meta.mainchar2CXOCSC identifier (JHHMMSS.s+DDMMSS)meta.idcharRAdeg[148.5/149.3]? Right Ascension (J2000)degpos.eq.ranullableDEdeg[68.9/69.2]? Declination (J2000)degpos.eq.decnullablelogLx[35.6/39.4] log X-ray luminosity; erg/slog(1e-07W)phys.luminosity;em.X-rayfloatVMag[-10.62/-0.55]? Absolute V band magnitude estimated at a distance of 3.63Mpcmagphys.magAbs;em.opt.VfloatnullableB-V[-2.2/3.6]? The (B-V) colormagphot.color;em.opt.B;em.opt.VfloatnullableV-I[-0.5/2.6]? The (V-I) colormagphot.color;em.opt.V;em.opt.IfloatnullableClassClassification (1)src.classcharf_Class[i] i = an XRB associated with a clustermeta.codecharCF[1/3] Confidence flag (1=most certain classifications) (2)meta.code.qualfloatSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from Lehmer+ 2019, J/ApJS/243/3 (right ascension part)degpos.eq.ra;meta.main_DEPositions from Lehmer+ 2019, J/ApJS/243/3 (declination part)degpos.eq.dec;meta.main