J/A+A/626/A50ivo://CDS.VizieR/J/A+A/626/A50doi:10.26093/cds/vizier.36260050CDSDufton P.L.Evans C.J.Hunter I.Lennon D.J.Schneider F.R.N.2019-10-02T08:42:23Z2019-10-02T09:38:19ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsstellar-associationsmorgan-keenan-classificationSpectroscopy for 247 stars towards the young cluster NGC 346 in the Small Magellanic Cloud has been combined with that for 116 targets from the VLT-FLAMES Survey of Massive Stars. Spectral classification yields a sample of 47 O-type and 287 B-type spectra, while radial-velocity variations and/or spectral multiplicity have been used to identify 45 candidate single-lined (SB1) systems, 17 double-lined (SB2) systems, and one triple-lined (SB3) system. Atmospheric parameters (T_eff_ and log g) and projected rotational velocities (v_e_sini) have been estimated usingTLUSTY model atmospheres; independent estimates of v_e_sini were also obtained using a Fourier Transform method. Luminosities have been inferred from stellar apparent magnitudes and used in conjunction with the T_eff_ and v_e_sini estimates to constrain stellar masses and ages using theBONNSAI package. We find that targets towards the inner region of NGC 346 have higher median masses and projected rotational velocities, together with smaller median ages than the rest of the sample. There appears to be a population of very young targets with ages of less than 2Myr, which have presumably all formed within the cluster. The more massive targets are found to have lower projected rotational velocities consistent with previous studies. No significant evidence is found for differences with metallicity in the stellar rotational velocities of early-type stars, although the targets in the Small Magellanic Cloud may rotate faster than those in young Galactic clusters. The rotational velocity distribution for single non-supergiant B-type stars is inferred and implies that a significant number have low rotational velocity (~=10% with v_e_<40km/s), together with a peak in the probability distribution at v_e_~=300km/s. Larger projected rotational velocity estimates have been found for our Be-type sample and imply that most have rotational velocities between 200-450km/s.2019A&A...626A..50Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/626/A50CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/PASP/98/1133 : The open cluster NGC 346 (Niemela+, 1986)J/AJ/98/1305 : Stellar content of NGC 346 (Massey+, 1989)J/A+A/456/623 : VLT-FLAMES survey of massive stars (Evans+, 2006)J/ApJS/166/549 : HST/ACS observations of NGC 346 (Gouliermis+, 2006)J/AJ/133/44 : NGC 346 HST VI photometry (Sabbi+, 2007)J/ApJ/672/914 : HST photometry in NGC 346 (Hennekemper+, 2008)J/A+A/515/A56 : NGC 346/N66 JHKs photometry (Gouliermis+, 2010)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/626/A50https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/626/A50http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/626/A50https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/626/A50https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/626/A50http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/626/A50GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/626/A50/tablea1 (Observational parameters of target stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/626/A50/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/626/A50/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/626/A50/tablea1?GETtext/xml+votable180.050000true14.7687083-72.17352780.0055555555555555566/33317 333283.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/626/A50?format=asciiOpticaldefaultJ/A+A/626/A50/tablea1Observational parameters of target starsSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStar[1001/1247] Star numbermeta.id;meta.mainintprimaryRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainrdRadial distance (1)arcminphys.angSizefloatVmagV magnitudemagphot.mag;em.opt.VfloatB-VB-V colour indexmagphot.color;em.opt.B;em.opt.VfloatSpTypeSpectral Typesrc.spTypecharn_Starindicates a note in notes.dat filemeta.ref.urlcharComComments (2)meta.notecharJ/A+A/626/A50/notesIndividual notesStarStar numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNoteNotemeta.notecharJ/A+A/626/A50/tablea2Atmospheric parameters (Teff, log g) and projected rotational velocities (vesini), luminosities, current masses and ages for the NGC 346 sampleStar[1/1247] Star numbermeta.id;meta.mainintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintn_Star[*] Note on Star (1)meta.notecharSpTypeSpectral Typesrc.spTypecharTeff? Effective temperatureKphys.temperature.effectiveintnullableMethodMethod used to estimate the effective temperature (2)meta.notecharlogg? Surface gravitylog(cm.s**-2)phys.gravityfloatnullablel_vesiniPF[<= ] Limit flag on vesiniPFmeta.code.errorcharvesiniPF? Projected rotational velocity estimated with the profile fitting (PF)km/sphys.veloc.rotatintnullablel_vesiniFT[<= ] Limit flag on vesiniFTmeta.code.errorcharvesiniFT? Projected rotational velocity estimated with the Fourier transform (FT)km/sphys.veloc.rotatintnullablerRadiusarcminphys.angSizefloatlogL? Luminositylog(solLum)phys.luminosityfloatnullableMass? MasssolMassphys.massfloatnullableAge? AgeMyrtime.agefloatnullableComComment (3)meta.notechar