J/ApJ/697/224ivo://CDS.VizieR/J/ApJ/697/224doi:10.26093/cds/vizier.16970224CDSHaggard D.Cool A.M.Davies M.B.2017-12-22T05:33:00Z2011-05-25T07:32:47ZCDS support team

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

cds-question@unistra.frglobular-star-clustersx-ray-sourcesastronomical-object-identificationWe analyze a ~70ks Chandra Advanced CCD Imaging Spectrometer exposure of the globular cluster {omega} Cen (NGC 5139). The ~17'x17' field of view fully encompasses three core radii and almost twice the half-mass radius. We detect 180 sources to a limiting flux of ~4.3x10^-16^erg/cm^2^/s (L_x_=1.2x10^30^erg/s at 4.9kpc). After accounting for the number of active galactic nuclei and possible foreground stars, we estimate that 45-70 of the sources are cluster members. Four of the X-ray sources have previously been identified as compact accreting binaries in the cluster - three cataclysmic variables (CVs) and one quiescent neutron star. Correlating the Chandra positions with known variable stars yields eight matches, of which five are probable cluster members that are likely to be binary stars with active coronae. Extrapolating these optical identifications to the remaining unidentified X-ray source population, we estimate that 20-35 of the sources are CVs and a similar number are active binaries. This likely represents most of the CVs in the cluster, but only a small fraction of all the active binaries.2009ApJ...697..224Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/697/224CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-)J/ApJ/663/1021 : Log of {omega} Cen scientific images (Castellani+, 2007)J/A+A/424/1101 : Variable Stars in the field of {omega} Cen (Kaluzny+, 2004)J/A+A/400/521 : Omega Cen XMM observations (Gendre+, 2003)J/ApJ/578/405 : Neutron stars in NGC 5139 (Rutledge+, 2002)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/697/224https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/697/224http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/697/224https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/697/224https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/697/224http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/697/224GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/697/224/table1 ({omega} Cen X-ray sources)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/697/224/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/697/224/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/697/224/table1?GETtext/xml+votable180.050000true201.6732917-47.47558330.0055555555555555566/43225 43227https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/697/224?format=asciiX-raydefaultJ/ApJ/697/224/table1{omega} Cen X-ray sourcesOptIDOptical ID (2)meta.id.crosscharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSource identification in this workmeta.id;meta.maincharCXOHCDIAU name (JHHMMSS.ss+DDMMSS.s)meta.idcharOffsetRadial offset from the cluster center in units of core radiipos.angDistancefloatMctsMedium band raw source counts (0.5-4.5keV)ctphot.count;em.X-rayintMctscMedium band corrected source counts (0.5-4.5keV)ctphot.count;em.X-rayfloatSctsSoft band raw source counts (0.5-1.5keV)ctphot.count;em.X-rayintSctscSoft band corrected source counts (0.5-1.5keV)ctphot.count;em.X-rayfloatHctsHard band raw source counts (1.5-6.0keV)ctphot.count;em.X-rayintHctscHard band corrected source counts (1.5-6.0keV)ctphot.count;em.X-rayfloatCtsRaw X-ray counts in the Chandra Deep Field South (CDFS) soft X-ray band (0.5-2.0keV)ctphot.count;em.X-rayintCtscCorrected X-ray counts in the Chandra Deep Field South (CDFS) soft X-ray band (0.5-2.0keV)ctphot.count;em.X-rayfloatS/H? Hardness ratiophot.flux;arith.ratiofloatnullableFxX-ray flux derived from the medium counts valuesmW.m**-2phot.flux;em.X-raydoubleONamePrevious X-ray ID references (1)meta.idcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from CXOHCD name (right ascension part)degpos.eq.ra;meta.main_DEPositions from CXOHCD name (declination part)degpos.eq.dec;meta.main