J/A+A/580/A93ivo://CDS.VizieR/J/A+A/580/A93doi:10.26093/cds/vizier.35800093CDSDunstall P.R.Dufton P.L.Sana H.Evans C.J.Howarth I.D.,Simon-Diaz S.de Mink S.E.Langer N.Maiz Apellaniz J.Taylor W.D.2017-12-22T05:32:55Z2015-08-07T09:45:53ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsb-starsspectroscopic-binary-starsradial-velocityWe investigate the multiplicity properties of 408 B-type stars observed in the 30 Doradus region of the Large Magellanic Cloud with multi-epoch spectroscopy from the VLT-FLAMES Tarantula Survey (VFTS). We use a cross-correlation method to estimate relative radial velocities from the helium and metal absorption lines for each of our targets. Objects with significant radial-velocity variations (and with an amplitude larger than 16km/s) are classified as spectroscopic binaries. We find an observed spectroscopic binary fraction (defined by periods of <10^3.5^d and mass ratios >0.1) for the B-type stars, f_B_(obs)=0.25+/-0.02, which appears constant across the field of view, except for the two older clusters (Hodge 301 and SL 639). These two clusters have significantly lower binary fractions of 0.08+/-0.08 and 0.10+/-0.09, respectively. Using synthetic populations and a model of our observed epochs and their potential biases, we constrain the intrinsic multiplicity properties of the dwarf and giant (i.e. relatively unevolved) B-type stars in 30 Dor. We obtain a present-day binary fraction f_B_(true)=0.58+/-0.11, with a flat period distribution. Within the uncertainties, the multiplicity properties of the B-type stars agree with those for the O stars in 30 Dor from the VFTS.2015A&A...580A..93Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/580/A93CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/530/A108 : VLT-FLAMES Tarantula Survey (Evans+, 2011)J/A+A/550/A107 : VLTS. RV catalogue of O stars in 30 Doradus (Sana+, 2013)J/A+A/550/A108 : DIB in VLT-FLAMES Tarantula Survey (van Loon+, 2013)J/A+A/550/A109 : VLTS: vsini measures (Dufton+ 2013)J/A+A/558/A134 : VLTS. 30 Dor luminous stars (Doran+, 2013)J/A+A/560/A29 : O-stars in VLT-FLAMES Tarantula Survey (Ramirez-Agudelo+ 2013)J/A+A/564/A39 : VLTS. OVz stars in 30 Dor (Sabin-Sanjulian+, 2014)J/A+A/564/A40 : VFTS. O-type stellar content of 30 Dor (Walborn+, 2014)J/A+A/564/L7 : VLT-FLAMES Tarantula Survey: VFTS 822 (Kalari+, 2014)J/A+A/575/A70 : VFTS. B-type supergiants (McEvoy+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/580/A93https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/580/A93http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/580/A93https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/580/A93https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/580/A93http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/580/A93GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/580/A93/stars (List of studied stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/580/A93/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/580/A93/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/580/A93/stars?GETtext/xml+votable180.050000true84.2224583-69.13841670.0055555555555555566/33094-33095https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/580/A93?format=asciiOpticaldefaultJ/A+A/580/A93/starsList of studied starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVFTS[1/891] VFTS star numbermeta.id;meta.mainintprimaryRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainNobs[4/16] Number of observationsmeta.numberintFileTable with RV data ("table2" or "table3")meta.idcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/580/A93/table2Relative RV estimates for each exposurerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVFTS[1/891] VFTS star numbermeta.id;meta.mainintT[*] Template spectrum for relative RV estimatesmeta.id;stat.fitcharS[BVS] Status: Binary, Variable or Singlemeta.codecharMJD[54748/55460] Modified Julian date of exposuredtime.epochdoubleSi4553? Relative RV estimate for SiIII line at 4553{AA}km/sspect.dopplerVelocfloatnullableO4080? Relative RV estimate for OII lines near 4080{AA}km/sspect.dopplerVelocfloatnullableO4317? Relative RV estimate for OII doublet near 4317{AA}km/sspect.dopplerVelocfloatnullableO4414? Relative RV estimate for OII doublet near 4414{AA}km/sspect.dopplerVelocfloatnullableHe4026? Relative RV estimate for HeI line at 4026{AA}km/sspect.dopplerVelocfloatnullableHe4471? Relative RV estimate for HeI line at 4471{AA}km/sspect.dopplerVelocfloatnullableHe4009? Relative RV estimate for HeI line at 4009{AA}km/sspect.dopplerVelocfloatnullableHe4144? Relative RV estimate for HeI line at 4144{AA}km/sspect.dopplerVelocfloatnullableHe4388? Relative RV estimate for HeI line at 4388{AA}km/sspect.dopplerVelocfloatnullableHe4121? Relative RV estimate for HeI line at 4121{AA}km/sspect.dopplerVelocfloatnullableHe4438? Relative RV estimate for HeI line at 4438{AA}km/sspect.dopplerVelocfloatnullableHe4169? Relative RV estimate for HeI line at 4169{AA}km/sspect.dopplerVelocfloatnullableJ/A+A/580/A93/table3Relative RV estimates for each epoch for stars with significant nebular contaminationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVFTS[1/891] Star numbermeta.id;meta.mainintT[*] Template spectrum for relative RV estimatesmeta.id;stat.fitcharS[BVS] Status: Binary, Variable or Singlemeta.codecharMJD[54767/55459] Modified Julian date of epochdtime.epochintHe4388? Relative RV estimate for He I line at 4388{AA}km/sspect.dopplerVelocfloatnullableHe4144? Relative RV estimate for He I line at 4144{AA}km/sspect.dopplerVelocfloatnullableHe4026? Relative RV estimate for He I line at 4026{AA}km/sspect.dopplerVelocfloatnullableHe4471? Relative RV estimate for He I line at 4471{AA}km/sspect.dopplerVelocfloatnullable