J/ApJ/738/129ivo://CDS.VizieR/J/ApJ/738/129doi:10.26093/cds/vizier.17380129CDSGuillot S.Rutledge R.E.Brown E.F.Pavlov G.G.Zavlin V.E.2017-09-18T12:52:39Z2017-08-22T13:00:59ZCDS support team

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

cds-question@unistra.frglobular-star-clustersx-ray-binary-starsThis paper reports the search for quiescent low-mass X-ray binaries (qLMXBs) in the globular cluster (GC) NGC 6553 using an XMM-Newton observation designed specifically for that purpose. We spectrally identify one candidate qLMXB in the core of the cluster, based on the consistency of the spectrum with a neutron star H-atmosphere model at the distance of NGC 6553. Specifically, the best-fit radius found using the three XMM European Photon Imaging Camera spectra is R_NS_=6.3^+2.3^_-0.8_ km (for M_NS_=1.4 M_{sun}_) and the best-fit temperature is kT_eff_=136^+21^_-34_ eV. Both physical parameters are in accordance with typical values of previously identified qLMXBs in GC and in the field, i.e., R_NS_~5-20 km and kT_eff_=50-150 eV. A power-law (PL) component with a photon index {Gamma}=2.1^+0.5^_-0.8_ is also required for the spectral fit and contributes ~33% of the total flux of the X-ray source. A detailed analysis supports the hypothesis that the PL component originates from nearby sources in the core, unresolved with XMM. The analysis of an archived Chandra observation provides marginal additional support to the stated hypothesis. Finally, a catalog of all the sources detected within the XMM field of view is presented here.2011ApJ...738..129Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/738/129CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/195 : Globular Clusters in the Milky Way (Harris, 1996)V/106 : Catalogue of X-ray binaries (Liu+ 2001)IX/50 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR6J/A+A/331/70 : JKVI photometry of NGC 6553 stars (Guarnieri+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/738/129https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/738/129http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/738/129https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/738/129https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/738/129http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/738/129GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/738/129/table1 (X-ray Sources Detected in the XMM Observation of NGC 6553)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/738/129/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/738/129/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/738/129/table1?GETtext/xml+votable180.050000true272.19551-26.01220.0055555555555555566/28882https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/738/129?format=asciidefaultJ/ApJ/738/129/table1X-ray Sources Detected in the XMM Observation of NGC 6553NameObject name (XMMU JHHMMSS+DDMMSS)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.maine_RAJ2000Uncertainty in RAdegarcsecstat.error;pos.eq.rafloatDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.maine_DEJ2000Uncertainty in DEdegarcsecstat.error;pos.eq.decfloatS/NDetection significance provided by wavdetectstat.snrfloatID[01/43] Source identifiermeta.idintJ/ApJ/738/129/table2Spectral Results of X-ray Sources in NGC 6553recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintID[01/43] Source identifiermeta.idintpnRateBackground subtracted count rates in the 0.3-10 keV rangect/ksphot.count;em.X-rayfloate_pnRateUncertainty in pnRatect/ksstat.errorfloatn_pnRate[a] Note on pnRate (1)meta.notecharGamma? Best-fit photon index when a power law (PL) model was usedmeta.code;spect.index;meta.modelledfloatnullablen_Gamma[)] Note on Gamma (2)meta.notecharE_Gamma? Upper limit uncertainty in Gammastat.error;stat.maxfloatnullablee_Gamma? Lower limit uncertainty in Gammastat.errorfloatnullablekTeff? Best-fit effective temperature when a thermal model was usedkeVphys.temperature.effectivefloatnullableE_kTeff? Upper limit uncertainty in kTeffkeVstat.error;stat.maxfloatnullablee_kTeff? Lower limit uncertainty in kTeffkeVstat.errorfloatnullablekTeff1? Best-fit effective temperature when a thermal model was usedkeVphys.temperature.effectivefloatnullableE_kTeff1? Upper limit uncertainty in kTeff1keVstat.error;stat.maxfloatnullablee_kTeff1? Lower limit uncertainty in kTeff1keVstat.errorfloatnullableFXUnabsorbed X-ray flux in the band 0.5-10 keV (10-13 erg/cm^2^/s) (3)1e-16W.m**-2phot.flux;em.X-rayfloatchi2{chi}^2^ statistic of the fitstat.weight;stat.fit.param;meta.modelledfloatdof[3/115] Number of degrees of freedommeta.numberintProb[0/1] Null hypothesis probabilitystat.probabilityfloatModelModel used (4)instr.setup;meta.modelledchar