J/MNRAS/442/1680ivo://CDS.VizieR/J/MNRAS/442/1680doi:10.26093/cds/vizier.74421680CDSDobbie P.D.Cole A.A.Subramaniam A.Keller S.2024-08-09T20:15:17Z2015-06-11T09:21:32ZCDS support team

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

cds-question@unistra.frmagellanic-cloudsgiant-starschemical-abundancesWe present results from the largest Caii triplet line metallicity study of Small Magellanic Cloud (SMC) field red giant stars to date, involving 3037 objects spread across approximately 37.5deg^2^, centred on this galaxy. We find a median metallicity of [Fe/H]=-0.99+/-0.01, with clear evidence for an abundance gradient of -0.075+/-0.011dex/deg over the inner 5{deg}. We interpret the abundance gradient to be the result of an increasing fraction of young stars with decreasing galactocentric radius, coupled with a uniform global age-metallicity relation. We also demonstrate that the age-metallicity relation for an intermediate-age population located 10kpc in front of the north-east of the cloud is indistinguishable from that of the main body of the galaxy, supporting a prior conjecture that this is a stellar analogue of the Magellanic Bridge. The metal-poor and metal-rich quartiles of our red giant branch star sample (with complementary optical photometry from the Magellanic Clouds Photometric Survey) are predominantly older and younger than approximately 6Gyr, respectively. Consequently, we draw a link between a kinematical signature, tentatively associated by us with a disc-like structure, and the upsurges in stellar genesis imprinted on the star formation history of the central regions of the SMC. We conclude that the increase in the star formation rate around 5-6Gyr ago was most likely triggered by an interaction between the SMC and Large Magellanic Cloud.2014MNRAS.442.1680Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/442/1680CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/304/347 : 40 field red supergiants in the SMC (Meliani+, 1995)J/AJ/123/855 : Magellanic Clouds Photometric Survey: SMC (Zaritsky+, 2002)J/AJ/131/2514 : Radial velocities of red giants in the SMC (Harris+, 2006)J/AJ/136/1039 : CaII index of SMC red giant branch stars (Carrera+, 2008)J/AJ/138/517 : CaII spectroscopy of SMC red giants (Parisi+, 2009)J/ApJ/754/35 : Red supergiant stars in the SMC. II. (Yang+, 2012)J/MNRAS/442/1663 : Red giants in the SMC. Velocities (Dobbie+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/442/1680https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/442/1680http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/442/1680https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/442/1680https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/442/1680http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/442/1680GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/442/1680/table1 (Details of the 3037 SMC red giant stars, including our CaII triplet equivalent width measurements and abundance estimates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/442/1680/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/442/1680/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/442/1680/table1?GETtext/xml+votable180.050000true0.1178333-75.55122220.005555555555555556Cone search capability for table J/MNRAS/442/1680/table4 (Details derived from the 1865 RGB star sources (1835 of which are unique) for which both V- and I-band photometry is available in the MCPS (Cat. J/AJ/123/855) and extinction levels can be estimated from the work of Haschke et al. (2011AJ....141..158H))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/442/1680/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/442/1680/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/442/1680/table4?GETtext/xml+votable180.050000true5.9839167-73.99063890.0055555555555555565/8238 8321-8324 8326 8329 8331-8333 6/32943 33300 33302 33308 33310-33313 33315 33321 33323 33336-33338 33409 33411-33414 33424 45317 453288.650015785639275e-20 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/442/1680?format=asciiOpticaldefaultJ/MNRAS/442/1680/table1Details of the 3037 SMC red giant stars, including our CaII triplet equivalent width measurements and abundance estimatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.main2MASS2MASS name (HHMMSSss+DDMMSSs)meta.id;meta.maincharprimary2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharNaSimbad column added by the CDSmeta.ref.urlintnullableJmag[14/15.2] 2MASS J magnitudemagphot.mag;em.IR.Jfloate_Jmag[0.02/0.08] rms uncertainty on Jmagmagstat.error;phot.mag;em.IR.JfloatKsmag[12.95/14.59] 2MASS Ks magnitudemagphot.mag;em.IR.Kfloate_Ksmag[0.02/0.11] rms uncertainty on Ksmagmagstat.error;phot.mag;em.IR.KfloatEW[0.16/9.1] CaII triplet equivalent width0.1nmspect.line.eqWidthfloate_EW[0.11/1.42] rms uncertainty on EW0.1nmstat.error;spect.line.eqWidthfloat[Fe/H][-3.28/-0.39] Metallicitylog(Sun)phys.abund.Zfloate_[Fe/H][0.06/0.47] rms uncertainty on [Fe/H]log(Sun)stat.error;phys.abund.FefloatPapIDisplay data of Paper I (Dobbie et al., 2014, Cat. J/MNRAS/442/1663)meta.ref.urlcharJ/MNRAS/442/1680/table4Details derived from the 1865 RGB star sources (1835 of which are unique) for which both V- and I-band photometry is available in the MCPS (Cat. J/AJ/123/855) and extinction levels can be estimated from the work of Haschke et al. (2011AJ....141..158H)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.main2MASS2MASS name (HHMMSSss+DDMMSSs)meta.id;meta.mainchar2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharVmag[16.18/19.21] V magnitudemagphot.mag;em.opt.Vfloate_Vmag[0.02/0.47] rms uncertainty on Vmagmagstat.error;phot.mag;em.opt.VfloatAV[0.02/0.38] Absorption in V bandmagphot.mag;em.opt.VfloatImag[14.83/16.49] I magnitudemagphot.mag;em.opt.Ifloate_Imag[0.02/0.53] rms uncertainty on Imagmagstat.error;phot.mag;em.opt.IfloatAI[0.01/0.23] Absorption in I bandmagphot.mag;em.opt.IfloatAge[9/10.13] log(Age)log(Gyr)arith.zpfloate_Age[] rms uncertainty on log(Age)log(Gyr)stat.error;time.agefloat