J/A+A/618/A134ivo://CDS.VizieR/J/A+A/618/A134doi:10.26093/cds/vizier.36180134CDSMucciarelli A.Salaris M.Monaco L.Bonifacio P.Fu X.Villanova S.2018-12-03T15:03:27Z2018-10-23T09:37:06ZCDS support team

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

cds-question@unistra.fropen-star-clusterspopulation-ii-starschemical-abundancesWe present Li, Na, Al and Fe abundances of 199 lower red giant branch stars members of the stellar system Omega Centauri, using high-resolution spectra acquired with FLAMES at the Very Large Telescope. The A(Li) distribution is peaked at A(Li)~1dex with a prominent tail toward lower values. The peak of the distribution well agrees with the lithium abundances measured in lower red giant branch stars in globular clusters and Galactic field stars. Stars with A(Li)~1dex are found at metallicities lower than [Fe/H]~-1.3dex but they disappear at higher metallicities. On the other hand, Li-poor stars are found at all the metallicities. The most metal-poor stars exhibit a clear Li-Na anticorrelation, with about 30% of the sample with A(Li) lower than ~0.8dex, while in normal globular clusters these stars represent a small fraction. Most of the stars with [Fe/H]>-1.6dex are Li-poor and Na-rich. The Li depletion measured in these stars is not observed in globular clusters with similar metallicities and we demonstrate that it is not caused by the proposed helium enhancements and/or young ages. Hence, these stars formed from a gas already depleted in lithium. Finally, we note that Omega Centauri includes all the populations (Li-normal/Na-normal, Li-normal/Na-rich and Li-poor/Na-rich stars) observed, to a lesser extent, in mono-metallic GCs.2018A&A...618A.134Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/618/A134CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/493/959 : UBV(RI)cHalpha photometry in omega Cen (Bellini+, 2009)J/AJ/135/1395 : omega Cen Spitzer photometry (Boyer+, 2008)J/A+A/360/472 : Proper motions in omega Centauri (van Leeuwen+, 2000)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/618/A134https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/618/A134http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/618/A134https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/618/A134https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/618/A134http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/618/A134GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/618/A134/table1 (Main information on the observed FLAMES targets)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/618/A134/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/618/A134/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/618/A134/table1?GETtext/xml+votable180.050000true201.72313694-47.661730.0055555555555555566/43225 432278.650015785639275e-20 4.920466254354166e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/618/A134?format=asciidefaultJ/A+A/618/A134/table1Main information on the observed FLAMES targetsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identification number (1)meta.id;meta.mainintRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainBmagJohnson B magnitudemagphot.mag;em.opt.BfloatVmagJohnson V magnitudemagphot.mag;em.opt.VfloatImagCousins I magnitudemagphot.mag;em.opt.IfloatKsmag? 2MASS Ks magnitudemagphot.mag;em.IR.KfloatnullableRVRadial velocitykm/sphys.veloc;pos.heliocentricfloate_RVUncertainty on RVkm/sstat.errorfloatJ/A+A/618/A134/table2Relative abundances of the FLAMES targetsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStar identification numbermeta.id;meta.mainintTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravitylog(cm.s**-2)phys.gravityfloatVtMicroturbulent velocitykm/sphys.velocfloat[Fe/H]Relative abundance [Fe/H]log(Sun)phys.abund.Fefloate_[Fe/H]Uncertainty on [Fe/H]log(Sun)stat.error;phys.abund.Fefloatl_A(Li)Upper limit flag on A(Li)meta.code.errorcharA(Li)Absolute abundance A(Li)phys.abundfloate_A(Li)? Uncertainty on A(Li)stat.errorfloatnullable[Na/Fe]Relative abundance [Na/Fe]log(Sun)phys.abundfloate_[Na/Fe]Uncertainty on [Na/Fe]log(Sun)stat.error;phys.abundfloatl_[Al/Fe]Upper limit flag on [Al/Fe]meta.code.error;phys.abundchar[Al/Fe]Relative abundance [Al/Fe]log(Sun)phys.abundfloate_[Al/Fe]? Uncertainty on [Al/Fe]log(Sun)stat.error;phys.abundfloatnullable