J/A+A/609/A13ivo://CDS.VizieR/J/A+A/609/A13doi:10.26093/cds/vizier.36090013CDSKoch A.Hansen T.Kunder A.2018-03-12T08:26:00Z2017-12-22T20:01:30ZCDS support team

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

cds-question@unistra.fropen-star-clustersspectroscopyline-intensitiesStar clusters, particularly those objects in the disk-bulge-halo interface are as yet poorly charted, despite the fact that they carry important information about the formation and the structure of the Milky Way. Here, we present a detailed chemical abundance study of the recently discovered object Gaia 1. Photometry has previously suggested it as an intermediate-age, moderately metal-rich system, although the exact values for its age and metallicity remained ambiguous in the literature. We measured detailed chemical abundances of 14 elements in four red giant members, from high-resolution (R=25000) spectra that firmly establish Gaia 1 as an object associated with the thick disk. The resulting mean Fe abundance is -0.62+/-0.03(stat.)+/-0.10(sys.) dex, which is more metal-poor than indicated by previous spectroscopy from the literature, but it is fully in line with values from isochrone fitting. We find that Gaia 1 is moderately enhanced in the {alpha}-elements, which allowed us to consolidate its membership with the thick disk via chemical tagging. The cluster's Fe-peak and neutron-capture elements are similar to those found across the metal-rich disks, where the latter indicate some level of s-process activity. No significant spread in iron nor in other heavy elements was detected, whereas we find evidence of light-element variations in Na, Mg, and Al. Nonetheless, the traditional Na-O and Mg-Al (anti-)correlations, typically seen in old globular clusters, are not seen in our data. This confirms that Gaia 1 is rather a massive and luminous open cluster than a low-mass globular cluster. Finally, orbital computations of the target stars bolster our chemical findings of Gaia 1's present-day membership with the thick disk, even though it remains unclear which mechanisms put it in that place.2018A&A...609A..13Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/609/A13CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/565/A23 : Abundances of NGC5897 red giants (Koch+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/609/A13https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/609/A13http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/609/A13https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/609/A13https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/609/A13http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/609/A13GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/609/A13/table1 (Observing log and target properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/609/A13/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/609/A13/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/609/A13/table1?GETtext/xml+votable180.050000true101.457375-16.74624170.0055555555555555566/20934 209407.952274030004205e-20 1.7798557115773645e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/609/A13?format=asciiOpticaldefaultJ/A+A/609/A13/table1Observing log and target propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintEWDisplay the EW data in table2meta.ref.urlcharStarStar sequential numbermeta.recordintRAJ2000Rigth ascension (J2000.0)pos.eq.ra;meta.mainDEJ2000Declination (J2000.0)pos.eq.dec;meta.mainJmagJ magnitudemagphot.mag;em.IR.JfloatHmagH magnitudemagphot.mag;em.IR.HfloatKmagK magnitudemagphot.mag;em.IR.KfloatObs.DateDate of observationtime.epochnullabletexpExposure timestime.duration;obs.exposurecharSN6550Signal-to-noise ration measured at 6550{AA}stat.snrintSN5500Signal-to-noise ration measured at 5500{AA}stat.snrintSN4500Signal-to-noise ration measured at 4500{AA}stat.snrintHVHeliocentric velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HVrms uncertainty on HVkm/sstat.errorfloatJ/A+A/609/A13/table2Line listn_EW2[s] s for synmeta.notecharn_EW1[s] s for synmeta.notecharn_EW4[s] s for synmeta.notecharn_EW3[s] s for synmeta.notecharEW4? Equivalent width for Star 4 (1)1e-13mspect.line.eqWidthintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonIon designationphys.atmol.ionStagefloatlambdaWavelength0.1nmem.wlfloatEPExcitation potentialeVphys.atmol.excitationfloatloggfOscillator strengthphys.atmol.oscStrengthfloatEW1? Equivalent width for Star 1 (1)1e-13mspect.line.eqWidthintnullableEW2? Equivalent width for Star 2 (1)1e-13mspect.line.eqWidthintnullableEW3? Equivalent width for Star 3 (1)1e-13mspect.line.eqWidthintnullable