J/AJ/135/836ivo://CDS.VizieR/J/AJ/135/836doi:10.26093/cds/vizier.51350836CDSCarrera R.Gallart C.Hardy E.Aparicio A.Zinn R.2010-08-06T17:10:39Z2010-07-21T14:27:21ZCDS support team

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

cds-question@unistra.frgiant-starsmagellanic-cloudsinfrared-astronomyspectroscopyradial-velocityinfrared-photometryvisible-astronomyphotometryInfrared CaII triplet (CaT) spectroscopy has been used to derive stellar metallicities for individual stars in four Large Magellanic Cloud fields situated at galactocentric distances of 3{deg}, 5{deg}, 6{deg}, and 8{deg} to the north of the bar. The combination of spectroscopy with deep CCD photometry has allowed us to break the RGB age-metallicity degeneracy and compute the ages for the objects observed spectroscopically. The obtained age-metallicity relationships (AMRs) for our four fields are statistically indistinguishable. We conclude that the lower mean metallicity in the outermost field is a consequence of it having a lower fraction of intermediate-age stars, which are more metal-rich than the older stars. The disk AMR is similar to that for clusters. However, the lack of objects with ages between 3 and 10Gyr is not observed in the field population. Finally, we used data from the literature to derive consistently the AMR of the bar. Simple chemical evolution models have been used to reproduce the observed AMRs with the purpose of investigating which mechanism has participated in the evolution of the disk and bar.2008AJ....135..836Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/135/836CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/480/379 : Abundances of 59 red giants in LMC (Pompeia+, 2008)J/AJ/134/1298 : CaII equivalent widths in 29 Galactic clusters (Carrera+, 2007)J/AJ/129/1465 : Spectroscopy of red giants in the LMC bar (Cole+, 2005)J/AJ/120/1808 : Stroemgren photometry in LMC disk (Cole+, 2000)J/AJ/116/723 : LMC star clusters ages and metallicity (Bica+ 1998)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/135/836https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/135/836http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/135/836https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/135/836https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/135/836http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/135/836GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/135/836/table1 (LMC RGB stars observed)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/135/836/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/135/836/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/135/836/table1?GETtext/xml+votable180.050000true77.2246667-66.83197220.0055555555555555565/8456 6/33103 33124 33125 33137 33140 33141https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/135/836?format=asciiOpticalInfrareddefaultJ/AJ/135/836/table1LMC RGB stars observedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainW.CaTThe CaT index (1)0.1nmspect.line.eqWidthfloate_W.CaTThe 1{sigma} error in W.CaT0.1nmstat.errorfloatVmagThe V band magnitudemagphot.mag;em.opt.VfloatImagThe I band magnitudemagphot.mag;em.opt.IfloatRVRadial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_RVThe 1{sigma} error in RVkm/sstat.errorfloatCommAdditional comment ("No member", "AGB" or "low S/N") (2)meta.code.memberchar