J/ApJ/709/241ivo://CDS.VizieR/J/ApJ/709/241doi:10.26093/cds/vizier.17090241CDSBogdanov S.van den Berg M.Heinke C.O.Cohn H.N.Lugger P.M.,Grindlay J.E.2017-09-20T05:14:08Z2012-03-29T09:56:05ZCDS support team

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

cds-question@unistra.frglobular-star-clustersx-ray-sourcespulsarsWe present a deep Chandra X-ray Observatory study of the peculiar binary radio millisecond pulsar (MSP) PSR J1740-5340 and candidate millisecond pulsars in the globular cluster NGC 6397. The X-rays from PSR J1740-5340 appear to be non-thermal and exhibit variability at the binary period. These properties suggest the presence of a relativistic intrabinary shock formed due to interaction of a relativistic rotation-powered pulsar wind and outflow from the unusual "red-straggler/sub-subgiant" companion. We find the X-ray source U18 to show similar X-ray and optical properties to those of PSR J1740-5340, making it a strong MSP candidate. It exhibits variability on timescales from hours to years, also consistent with an intrabinary shock origin of its X-ray emission. The unprecedented depth of the X-ray data allows us to conduct a complete census of MSPs in NGC 6397. Based on the properties of the present sample of X-ray-detected MSPs in the Galaxy, we find that NGC 6397 probably hosts no more than six MSPs.2010ApJ...709..241Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/709/241CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/chandra : The Chandra Archive Log (CXC, 1999-)B/hst : HST Archived Exposures Catalog (STScI, 2007)J/A+A/505/L13 : Lithium in globular NGC 6397 (Gonzalez Hernandez+, 2009)J/A+A/503/545 : Equivalent widths of Li, Na, Fe, Ca in NGC 6397 (Lind+, 2009)J/A+A/490/777 : Abundances of Population II stars in NGC 6397 (Lind+, 2008)J/A+A/425/509 : VI photometry of NGC 6397 (Andreuzzi+, 2004)J/A+AS/122/1 : BV photometry of variables in NGC 6397 (Kaluzny, 1997)J/AJ/110/1699 : F-P observations of globular clusters (Gebhardt+ 1995)J/A+A/287/769 : UV photometry of NGC 6397 (Burgarella+ 1994)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/709/241https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/709/241http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/709/241https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/709/241https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/709/241http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/709/241GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/709/241/table3 (X-ray sources in NGC 6397)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/709/241/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/709/241/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/709/241/table3?GETtext/xml+votable180.050000true265.2272125-53.679047220.0055555555555555566/42076https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/709/241?format=asciiX-rayRadiodefaultJ/ApJ/709/241/table3X-ray sources in NGC 6397recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[5,123] Source names based on the X-ray source list from Grindlay et al. (2001ApJ...563L..53G; <[GHE2001b] UNNN> in Simbad)meta.id;meta.mainintCXOGlbCXOGlb name (HHMMSS.s+DDMMSS; J2000)meta.idcharRAJ2000Hour of right ascension (J2000) (1)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000) (1)pos.eq.dec;meta.mainr95The 95% positional uncertainty radius (2)arcsecstat.error;phys.angSizefloatSctsSoft X-ray counts in 0.5-1.5keV band (3)ctphot.count;em.X-rayintHctsHard X-ray counts in 1.5-6keV band (3)ctphot.count;em.X-rayintFluxFlux in 0.5-6keV band (4)1e-19W.m**-2phot.flux;em.X-ray.mediumfloatTypeProbable source identifications (5)src.classcharSimbadSimbad column added by the CDSchar