J/ApJ/868/57ivo://CDS.VizieR/J/ApJ/868/57doi:10.26093/cds/vizier.18680057CDSCastro N.Oey M.S.Fossati L.Langer N.2020-03-26T14:17:48Z2019-11-20T14:28:49ZCDS support team

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

cds-question@unistra.frob-starsmagellanic-cloudseffective-temperaturestellar-massesWe present a comprehensive stellar atmosphere analysis of 329 O- and B-type stars in the Small Magellanic Cloud (SMC) from the RIOTS4 survey. Using spectroscopically derived effective temperature Teff and surface gravities, we find that classical Be stars appear misplaced to low Teff and high luminosity in the spectroscopic Hertzsprung-Russell diagram (sHRD). Together with the most luminous stars in our sample, the stellar masses derived from the sHRD for these objects are systematically larger than those obtained from the conventional Hertzsprung-Russell diagram. This suggests that the well-known, spectroscopic mass-discrepancy problem may be linked to the fact that both groups of stars have outer envelopes that are nearly gravitationally unbound. The non-emission-line stars in our sample mainly appear on the main sequence, allowing a first estimate of the terminal-age main sequence (TAMS) in the SMC, which matches the predicted TAMS between 12 and 40M_{sun}_ at SMC metallicity. We further find a large underabundance of stars above ~25M_{sun}_ near the zero-age main sequence, reminiscent of such earlier findings in the Milky Way and Large Magellanic Cloud.2018ApJ...868...57Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/868/57CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/236 : UBVR CCD survey of the Magellanic clouds (Massey+, 2002)J/MNRAS/353/601 : 2dF survey of the Small Magellanic Cloud (Evans+, 2004)J/AJ/127/1632 : UBVR(UIT) photometry of O and OB stars in SMC (Oey+, 2004)J/ApJ/659/1198 : ARAUCARIA project: NGC 3109 blue supergiants (Evans+, 2007)J/A+A/471/625 : VLT-FLAMES survey of massive stars (Trundle+, 2007)J/AJ/140/416 : IR photometry of massive stars in the SMC (Bonanos+, 2010)J/A+A/530/A115 : Rotating massive MS stars evolutionary models (Brott+, 2011)J/A+A/532/A147 : HST photometry in extragalactic star clusters (Larsen+, 2011)J/A+A/537/A146 : Stellar models with rotation. Z=0.014 (Ekstrom+, 2012)J/A+A/539/A143 : Nearby B-stars stellar param. and abundances (Nieva+, 2012)J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)J/A+A/558/A103 : Stellar models with rotation. Z=0.002 (Georgy+, 2013)J/MNRAS/442/1680 : Red giants in SMC. Abundances (Dobbie+, 2014)J/ApJ/780/59 : The Araucaria project: EBs in SMC (Graczyk+, 2014)J/A+A/591/A11 : SMC BV photometry of 9 star cluster fields (Dias+, 2016)J/ApJ/817/113 : RIOTS4: spec. survey of SMC field OB stars (Lamb+, 2016)J/ApJ/816/49 : Spitzer/IRAC observations of SMC Cepheids (Scowcroft+, 2016)J/A+A/600/A81 : VLTS. 30Dor O giants & supergiants (Ramirez-Agudelo+, 2017)J/A+A/601/A79 : VLTS. O dwarf in 30 Dor (Sabin-Sanjulian+, 2017)J/A+A/597/A22 : Massive O- and B-type stars velocities (Simon-Diaz+, 2017)J/A+A/613/A65 : Spectroscopic parameters of O-type stars (Holgado+, 2018)J/ApJ/867/L8 : Gaia kinematic data of OB stars in SMC (Oey+, 2018)J/other/Sci/359.69 : Massive stars in 30 Dor (Schneider+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/868/57https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/868/57http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/868/57https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/868/57https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/868/57http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/868/57GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/868/57/table1 (OB in the SMC analyzed in this work)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/868/57/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/868/57/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/868/57/table1?GETtext/xml+votable180.050000true14.1840417-72.05869440.0055555555555555565/8326 6/33294 33295 33297 33298 33299 33316 33317 33319 33328https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/868/57?format=asciidefaultJ/ApJ/868/57/table1OB in the SMC analyzed in this workrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDMassey 2002, II/236 identifier; <[M2002] SMC NNNNN> in Simbadmeta.idintRAJ2000[0/1] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[71/73] Degree of Declination (J2000)pos.eq.dec;meta.mainlogTeff[4/4.7] log effective temperaturelog(K)phys.temperature.effectivefloate_logTeff[0/0.2] Uncertainty in logTefflog(K)stat.error;phys.temperature.effectivefloatlogLs[2.7/4.6] log spectroscopic luminosity (1)log(solLum)phys.luminosityfloate_logLs[-0/0.7] Uncertainty in logLslog(solLum)stat.errorfloatlogL[0/6] log luminositylog(solLum)phys.luminosityfloate_logL[0/0.4] Uncertainty in logLlog(solLum)stat.errorfloatlogMsHRD[0.7/2]? log estimated mass in the spectroscopic Hertzsprung-Russell diagram (sHRD)(1)log(solMass)phys.massfloatnullablelogMHRD[0.7/1.7]? log estimated mass in the Hertzsprung-Russell diagram (HRD)log(solMass)phys.massfloatnullableEm[e] Balmer line emission flag (2)meta.codecharMet[m] Metals flag (2)meta.codecharSCatDisplay data from RIOTS4 (Lamb+, 2016, J/ApJ/817/113); Evans+, 2004, J/MNRAS/353/601 and Bonanos+, 2010, J/AJ/140/416 within 1"meta.ref.urlintnullableSimbadSimbad column added by the CDSmeta.ref.urlchar