J/AJ/149/154ivo://CDS.VizieR/J/AJ/149/154doi:10.26093/cds/vizier.51490154CDSParisi M.C.Geisler D.Claria J.J.Villanova S.Marcionni N.,Sarajedini A.Grocholski A.J.2018-05-29T17:31:11Z2015-06-08T14:52:15ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsstellar-associationsgiant-starsline-intensitiesmetallicityWe obtained spectra of red giants in 15 Small Magellanic Cloud (SMC) clusters in the region of the CaII lines with FORS2 on the Very Large Telescope. We determined the mean metallicity and radial velocity with mean errors of 0.05dex and 2.6km/s, respectively, from a mean of 6.5 members per cluster. One cluster (B113) was too young for a reliable metallicity determination and was excluded from the sample. We combined the sample studied here with 15 clusters previously studied by us using the same technique, and with 7 clusters whose metallicities determined by other authors are on a scale similar to ours. This compilation of 36 clusters is the largest SMC cluster sample currently available with accurate and homogeneously determined metallicities. We found a high probability that the metallicity distribution is bimodal, with potential peaks at -1.1 and -0.8dex. Our data show no strong evidence of a metallicity gradient in the SMC clusters, somewhat at odds with recent evidence from CaII triplet spectra of a large sample of field stars. This may be revealing possible differences in the chemical history of clusters and field stars. Our clusters show a significant dispersion of metallicities, whatever age is considered, which could be reflecting the lack of a unique age-metallicity relation in this galaxy. None of the chemical evolution models currently available in the literature satisfactorily represents the global chemical enrichment processes of SMC clusters.2015AJ....149..154Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/149/154CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/517/A50 : Ages & luminosities of SMC/LMC star clusters (Glatt+, 2010)J/AJ/139/1168 : CaII spectroscopy of SMC fields stars (Parisi+, 2010)J/AJ/138/517 : CaII spectroscopy of SMC red giants (Parisi+, 2009)J/AJ/136/1039 : CaII index of SMC red giant branch stars (Carrera+, 2008)J/AJ/132/1630 : CaII spectroscopy in Magellanic Cloud clustersJ/A+A/440/111 : Spectra of SMC star clusters (Piatti+, 2005)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/149/154https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/149/154http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/149/154https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/149/154https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/149/154http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/149/154GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/149/154/table1 (Small Magellanic Cloud (SMC) clusters sample)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/149/154/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/149/154/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/149/154/table1?GETtext/xml+votable180.050000true15.1271667-73.08733330.0055555555555555566/32953 32958 33287 33293 33295 33306 33313 33315 33320 33329 33330https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/149/154?format=asciidefaultJ/AJ/149/154/table1Small Magellanic Cloud (SMC) clusters sampleSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster namemeta.id;meta.maincharprimaryNsNumber of stars in clustermeta.numberintnullableONameOther cluster name(s)meta.idcharRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.maina[0.5/7.6] Semimajor axis (from SMC centre)degphys.angSize.smajAxisfloatAge[0.5/7.5] Age adoptedGyrtime.agefloatr_Age[1/9] Bibliographic reference for Age (1)meta.ref;pos.frameintJ/AJ/149/154/table2Measured values for member starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintClusterCluster namemeta.id.parentcharStar[1/33] ID for cluster member starmeta.idintHRV[103/211] Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV? The 1{sigma} error in HRVkm/sstat.error;spect.dopplerVeloc;pos.heliocentricfloatnullableV-VHB[-3.28/0.03]? Brightness difference between star and cluster's horizontal branchmagphot.mag;arith.difffloatnullableWCaII[4.8/9.1]? Summed CaII equivalent width {Sigma}W (1)0.1nmspect.line.eqWidthfloatnullablee_WCaII? The 1{sigma} error in WCaII0.1nmstat.error;spect.line.eqWidthfloatnullable[Fe/H][-1.31/-0.54]? Metallicitylog(Sun)phys.abund.Zfloatnullablee_[Fe/H]? The 1{sigma} error in [Fe/H]log(Sun)stat.error;phys.abund.Fefloatnullable