J/A+A/445/155ivo://CDS.VizieR/J/A+A/445/155doi:10.26093/cds/vizier.34450155CDSWebb N.A.Wheatley P.J.Barret D.2006-01-12T21:27:33Z2006-01-12T22:27:21ZCDS support team

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

cds-question@unistra.frglobular-star-clustersx-ray-sourcesWe have observed two low concentration Galactic globular clusters with the X-ray observatory XMM-Newton. We detect 47 faint X-ray sources in the direction of M 55 and 62 in the field of view of NGC 3201. Using the statistical LogN-LogS relationship of extragalactic sources derived from XMM-Newton Lockman Hole observations, to estimate the background source population, we estimate that very few of the sources (1.5+/-1.0) in the field of view of M 55 actually belong to the cluster. These sources are located in the centre of the cluster as we expect if the cluster has undergone mass segregation. NGC 3201 has approximately 15 related sources, which are centrally located but are not constrained to lie within the half mass radius. The sources belonging to this cluster can lie up to 5 core radii from the centre of the cluster which could imply that this cluster has been perturbed. Using X-ray (and optical, in the case of M 55 ) colours, spectral and timing analysis (where possible) and comparing these observations to previous X-ray observations, we find evidence for sources in each cluster that could be cataclysmic variables, active binaries, millisecond pulsars and possible evidence for a quiescent low mass X-ray binary with a neutron star primary, even though we do not expect any such objects in either of the clusters, due to their low central concentrations. The majority of the other sources are background sources, such as AGN.2006A&A...445..155Whttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/445/155CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/309/116 : 10 globular cluster ROSAT observations (Johnston+, 1996)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/445/155https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/445/155http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/445/155https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/445/155https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/445/155http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/445/155GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/445/155/Xsrc (0.5-10.0keV band.)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/445/155/Xsrc?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/445/155/Xsrc?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/445/155/Xsrc?GETtext/xml+votable180.050000true295.121-31.16510.0055555555555555566/38465 47970-47971https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/445/155?format=asciiX-raydefaultJ/A+A/445/155/Xsrc0.5-10.0keV band.recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterClustercharSeqIdentification number given in this paperintn_Seq[ch] Note as to whether it is in the core (1)charRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.maine_PosError in the positionarcsecfloatCRCount rate in the 0.5-10.0keV band0.001count.s**-1floate_CRCount rate error0.001count.s**-1float[JVH96]Johnson et al. (1996, Cat. <J/A+A/309/116> number (2)char