J/A+A/298/115ivo://CDS.VizieR/J/A+A/298/115doi:10.26093/cds/vizier.32980115CDSRandich S.Schmitt J.H.M.M.1999-07-29T16:22:07Z1999-07-29T16:21:55ZCDS support team

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

cds-question@unistra.fropen-star-clustersx-ray-sourcesWe present the results of the ROSAT PSC observations of the Praesepe cluster. 68 Praesepe candidates have been detected, above a threshold of ~2x10^+28^erg/s (2x10^21^W), in the ~4degx4deg area of the cluster covered by the observations. 56 out of the 68 detected objects are cataloged as high probability Praesepe members.1995A&A...298..115Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/298/115CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/298/115https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/298/115http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/298/115https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/298/115https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/298/115http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/298/115GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/298/115/table2 (Optical properties of X-ray detected Praesepe candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/298/115/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/298/115/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/298/115/table2?GETtext/xml+votable180.050000true129.2587519.60463890.005555555555555556Cone search capability for table J/A+A/298/115/table5 (Undetected Praesepe candidates lying in the low sensitivity image region)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/298/115/table5?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/298/115/table5?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/298/115/table5?GETtext/xml+votable180.050000true129.8937520.9558330.005555555555555556https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/298/115?format=asciiX-raydefaultJ/A+A/298/115/table2Optical properties of X-ray detected Praesepe candidatesNotesNotesmeta.notecharVmagV magnitudemagphot.mag;em.opt.VfloatB-V[]? B-V colourmagphot.color;em.opt.B;em.opt.VfloatnullableV-I[]? V-I colourmagphot.color;em.opt.V;em.opt.IfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintId[1/68] X-ray numbermeta.id;meta.mainintOtherIdOptical identification (1)meta.idcharRAJ2000Right ascension J2000pos.eq.ra;meta.mainDEJ2000Declination J2000pos.eq.dec;meta.mainProba[]? Membership probability%stat.fit.goodnessintnullablen_Proba[p] A 'p' means possiblemeta.notecharSpSpectral typesrc.spTypecharJ/A+A/298/115/table4X-ray properties of the detected Praesepe candidatesn_Id[*] Notemeta.notecharHardRHardness ratiophot.flux;arith.ratiofloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIdX-ray numbermeta.id;meta.mainintMLMaximum Likelihood (ML) algorithmstat.likelihoodfloatdRA[]? Offset in right ascensionarcsecpos.eq.ra;arith.difffloatnullabledDE[]? Offset in declinationarcsecpos.eq.dec;arith.difffloatnullablectCountsct/sphot.count;em.X-rayfloate_ctrms uncertainty on counts (1 sigma error)ct/sstat.errorfloatLxX-ray luminosity1e+22Wphys.luminosity;em.X-rayfloate_Lxrms uncertainty on Lx (1 sigma error)1e+22Wstat.errorfloatLx/LbolX-ray over bolometric luminosityphys.luminosity;arith.ratiodoublel_HardR[>] limit flag on HardRmeta.code.errorcharJ/A+A/298/115/table5Undetected Praesepe candidates lying in the low sensitivity image regionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar namemeta.id;meta.maincharRAJ2000Right ascension J2000pos.eq.ra;meta.mainDEJ2000Declination J2000pos.eq.dec;meta.mainVV magnitudemagphot.mag;em.opt.VfloatB-V[]? B-V colourmagphot.color;em.opt.B;em.opt.VfloatnullableV-I[]? V-I colourmagphot.color;em.opt.V;em.opt.IfloatnullableProbaMembership probability%stat.fit.goodnessintUpctUpper limit on countsct/sphot.count;em.X-rayfloatLxUpper limit on X-ray luminosity (10^29^erg/s)1e+22Wphys.luminosity;em.X-rayfloat