J/A+A/631/A14ivo://CDS.VizieR/J/A+A/631/A14doi:10.26093/cds/vizier.36310014CDSLatour M.Husser T.-O.Giesers B.Kamann S.Goettgens F.Dreizler S.,Brinchmann J.Bastian N.Wendt M.Weilbacher P.M.Molinski N.S.2019-10-11T06:10:44Z2019-10-11T07:05:57ZCDS support team

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

cds-question@unistra.frglobular-star-clustersstellar-populationsspectroscopyGalactic globular clusters (GCs) are now known to host multiple populations displaying particular abundance variations. The different populations within a GC can be well distinguished following their position in the pseudo two-colors diagrams, also referred to as "chromosome maps". These maps are constructed using optical and near-UV photometry available from the Hubble Space Telescope (HST) UV survey of GCs. However, the chemical tagging of the various populations in the chromosome maps is hampered by the fact that HST photometry and elemental abundances are both available only for a limited number of stars. The spectra collected as part of the MUSE survey of globular clusters provide a spectroscopic counterpart to the HST photometric catalogs covering the central regions of GCs. In this paper, we use the MUSE spectra of 1155 red giant branch (RGB) stars in NGC 2808 to characterize the abundance variations seen in the multiple populations of this cluster. We use the chromosome map of NGC 2808 to divide the RGB stars into their respective populations. We then combine the spectra of all stars belonging to a given population, resulting in one high signal-to-noise ratio spectrum representative of each population. Variations in the spectral lines of O, Na, Mg, and Al are clearly detected among four of the populations. In order to quantify these variations, we measured equivalent width differences and created synthetic populations spectra that were used to determine abundance variations with respect to the primordial population of the cluster. Our results are in good agreement with the values expected from previous studies based on high-resolution spectroscopy. We do not see any significant variations in the spectral lines of Ca, K, and Ba. We also do not detect abundance variations among the stars belonging to the primordial population of NGC 2808.2019A&A...631A..14Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/631/A14CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/413/343 : RGB stars in NGC 2808 (Cacciari+, 2004)J/A+A/480/397 : XMM observations of NGC 2808 and NGC 4372 (Servillat+, 2008)J/A+A/490/641 : X-ray sources toward NGC 2808 (Servillat+, 2008)J/A+A/528/A127 : Radial velocities in NGC 2808 (Moni Bidin+, 2011)J/A+A/534/A123 : Horizontal branch stars in NGC 2808 (Gratton+, 2011)J/A+A/542/A129 : NGC 2808 central kinematics (Luetzgendorf+, 2012)J/MNRAS/437/1609 : NGC 2808 HB stars abundances (Marino+, 2014)J/ApJ/810/148 : Red giant abundances in NGC 2808 (Carretta, 2015)J/A+A/586/A51 : JK photometry of NGC 2808 (Massari+, 2016)J/A+A/592/A66 : NGC 2808 AGB and RGB stars Na abundance (Wang+, 2016)J/A+A/615/A17 : Red giant Aluminium abundances in NGC 2808 (Carretta+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/631/A14https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/631/A14http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/631/A14https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/631/A14https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/631/A14http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/631/A14GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/631/A14/table (Star ID and population)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/631/A14/table?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/631/A14/table?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/631/A14/table?GETtext/xml+votable180.050000true138.0468161-64.87787090.0055555555555555566/37294https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/631/A14?format=asciidefaultJ/A+A/631/A14/tableStar ID and populationrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDID from the ACS Survey of Galactic Globular Clusters (1)meta.id;meta.mainintPop[1/4] Population number of the starsrc.classintRAJ2000Right ascension (J2000) (1)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (1)degpos.eq.dec;meta.mainJ/A+A/631/A14/listList of summed spectrarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNxNumber of pixels along X-axismeta.numberintbAWAVLower value of wavelength interval0.1nmem.wlintBAWAVUpper value of wavelength interval0.1nmem.wlfloatdAWAVWavelength resolution0.1nmspect.resolutionfloatsizeSize of FITS fileKibytephys.size;meta.fitsintspShow the summed spectrameta.ref.urlcharFileNameName of FITS file, in subdirectory fitsmeta.id;meta.fitscharTitleTitle of the FITS filemeta.title;meta.fitschar