J/AJ/149/204ivo://CDS.VizieR/J/AJ/149/204doi:10.26093/cds/vizier.51490204CDSSchaeuble M.Preston G.Sneden C.Thompson I.B.Shectman S.A.,Burley G.S.2017-06-26T11:48:58Z2015-06-17T08:12:28ZCDS support team

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

cds-question@unistra.frglobular-star-clustersgiant-starshorizontal-branch-starschemical-abundancesline-intensitiesIn this paper, we present a detailed high-resolution spectroscopic study of post main sequence stars in the globular cluster (GC) M68. Our sample, which covers a range of 4000K in T_eff_, and 3.5dex in log(g), is comprised of members from the red giant, red horizontal, and blue horizontal branch, making this the first high-resolution GC study covering such a large evolutionary and parameter space. Initially, atmospheric parameters were determined using photometric as well as spectroscopic methods, both of which resulted in unphysical and unexpected T_eff_, log(g), {xi}_t_, and [Fe/H] combinations. We therefore developed a hybrid approach that addresses most of these problems, and yields atmospheric parameters that agree well with other measurements in the literature. Furthermore, our derived stellar metallicities are consistent across all evolutionary stages, with <[Fe/H]>=-2.42 ({sigma}=0.14) from 25 stars. Chemical abundances obtained using our methodology also agree with previous studies and bear all the hallmarks of GCs, such as a Na-O anti-correlation, constant Ca abundances, and mild r-process enrichment.2015AJ....149..204Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/149/204CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/331 : M68 variable star light curves (Rosino+, 1953)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/AJ/132/85 : Equivalent width of 33 metal-poor RHB (Preston+, 2006)J/AJ/108/555 : BVI photometry in globular cluster M68 (Walker, 1994)J/AJ/107/622 : M68 variable star light curves (Brocato+, 1994)J/ApJ/412/183 : RR Lyr in M68 (Clement+, 1993)J/AJ/99/1831 : M 68 BVRI photometry (Alcaino+ 1990)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/149/204https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/149/204http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/149/204https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/149/204https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/149/204http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/149/204GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/149/204/stars (Photometric , and atmospheric parameters of the stars observed)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/149/204/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/149/204/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/149/204/stars?GETtext/xml+votable180.050000true189.8208333-26.76072220.0055555555555555566/248433.322582951404819e-19 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/149/204?format=asciiOpticaldefaultJ/AJ/149/204/starsPhotometric , and atmospheric parameters of the stars observedf_Star[ab] Flag on Star (1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStar[36/547] Star identification numbermeta.id;meta.mainintS/N[30/230] Signal-to-noise ratio (2)stat.snrintTeff1Photometric effective temperatureKphys.temperature.effectiveintlogg1Log of photometric surface gravitylog(cm.s**-2)phys.gravityfloatTeff2? Spectroscopic effective temperatureKphys.temperature.effectiveintnullablelogg2? Log of spectroscopic surface gravitylog(cm.s**-2)phys.gravityfloatnullableTeff[4168/7848] Adopted effective temperature (3)Kphys.temperature.effectiveintlogg[0.18/3.5] Adopted log of surface gravity (3)log(cm.s**-2)phys.gravityfloat[Fe/H][-2.65/-2.06] Adopted metallicity (3)phys.abund.ZfloatVt[1.97/3.81] Adopted microturbulent velocity {xi}t (3)km/sphys.velocfloatStageStar evolutionary stage (RGB, RHB, or BHB) (4)src.classcharVmag[12.6/15.8] The V-band magnitude (5)magphot.mag;em.opt.VfloatB-VThe (B-V) color index (5)magphot.color;em.opt.B;em.opt.VfloatV-IThe (V-I) color index (5)magphot.color;em.opt.V;em.opt.IfloatEWSimbad column added by the CDSmeta.ref.urlcharAbdSimbad column added by the CDSmeta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from SIMBAD database (right ascension part)degpos.eq.ra;meta.main_DEPositions from SIMBAD database (declination part)degpos.eq.dec;meta.mainJ/AJ/149/204/table3Equivalent widths for the 25 starsMethMethod of deriving abundance (EW or SYNTH) (2)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[3412/8195] Wavelength; in {AA}0.1nmem.wlfloatIonLine of atomic speciesphys.atmol.ionStagecharEP[0/10]? Line excitation potential (1)eVphys.atmol.excitation;spect.linefloatnullableloggf[-10/0.7]? The log oscillator strength (1)phys.atmol.oscStrengthfloatnullabler_loggf[1/19] Reference for log(gf); in refs.dat filemeta.ref;pos.frameintEW1? Measured Equivalent Width of star 57; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge1? The log{epsilon} abundance for star 57phys.abundfloatnullableEW2? Measured Equivalent Width of star 79; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge2? The log{epsilon} abundance for star 79phys.abundfloatnullableEW3? Measured Equivalent Width of star 117; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge3? The log{epsilon} abundance for star 117phys.abundfloatnullableEW4? Measured Equivalent Width of star 160; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge4? The log{epsilon} abundance for star 160phys.abundfloatnullableEW5? Measured Equivalent Width of star 172; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge5? The log{epsilon} abundance for star 172phys.abundfloatnullableEW6? Measured Equivalent Width of star 226; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge6? The log{epsilon} abundance for star 226phys.abundfloatnullableEW7? Measured Equivalent Width of star 256; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge7? The log{epsilon} abundance for star 256phys.abundfloatnullableEW8? Measured Equivalent Width of star 440; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge8? The log{epsilon} abundance for star 440phys.abundfloatnullableEW9? Measured Equivalent Width of star 450; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge9? The log{epsilon} abundance for star 450phys.abundfloatnullableEW10? Measured Equivalent Width of star 472; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge10? The log{epsilon} abundance for star 472phys.abundfloatnullableEW11? Measured Equivalent Width of star 481; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge11? The log{epsilon} abundance for star 481phys.abundfloatnullableEW12? Measured Equivalent Width of star 36; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge12? The log{epsilon} abundance for star 36phys.abundfloatnullableEW13? Measured Equivalent Width of star 47; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge13? The log{epsilon} abundance for star 47phys.abundfloatnullableEW14? Measured Equivalent Width of star 202; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge14? The log{epsilon} abundance for star 202phys.abundfloatnullableEW15? Measured Equivalent Width of star 334; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge15? The log{epsilon} abundance for star 334phys.abundfloatnullableEW16? Measured Equivalent Width of star 403; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge16? The log{epsilon} abundance for star 403phys.abundfloatnullableEW17? Measured Equivalent Width of star 454; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge17? The log{epsilon} abundance for star 454phys.abundfloatnullableEW18? Measured Equivalent Width of star 458; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge18? The log{epsilon} abundance for star 458phys.abundfloatnullableEW19? Measured Equivalent Width of star 533; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge19? The log{epsilon} abundance for star 533phys.abundfloatnullableEW20? Measured Equivalent Width of star 547; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge20? The log{epsilon} abundance for star 547phys.abundfloatnullableEW21? Measured Equivalent Width of star 170; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge21? The log{epsilon} abundance for star 170phys.abundfloatnullableEW22? Measured Equivalent Width of star 289; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge22? The log{epsilon} abundance for star 289phys.abundfloatnullableEW23? Measured Equivalent Width of star 324; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge23? The log{epsilon} abundance for star 324phys.abundfloatnullableEW24? Measured Equivalent Width of star 337; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge24? The log{epsilon} abundance for star 337phys.abundfloatnullableEW25? Measured Equivalent Width of star 391; in m{AA}0.1pmspect.line.eqWidthfloatnullableloge25? The log{epsilon} abundance for star 391phys.abundfloatnullableJ/AJ/149/204/table8Average abundances for individual starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint[X/Fe]Ionphys.atmol.ionStagechar<Abd1>? The average [X/Fe] abundance for Star 57log(Sun)stat.mean;phys.abundfloatnullable<Abd2>? The average [X/Fe] abundance for Star 79log(Sun)stat.mean;phys.abundfloatnullable<Abd3>? The average [X/Fe] abundance for Star 117log(Sun)stat.mean;phys.abundfloatnullable<Abd4>? The average [X/Fe] abundance for Star 160log(Sun)stat.mean;phys.abundfloatnullable<Abd5>? The average [X/Fe] abundance for Star 172log(Sun)stat.mean;phys.abundfloatnullable<Abd6>? The average [X/Fe] abundance for Star 226log(Sun)stat.mean;phys.abundfloatnullable<Abd7>? The average [X/Fe] abundance for Star 256log(Sun)stat.mean;phys.abundfloatnullable<Abd8>? The average [X/Fe] abundance for Star 440log(Sun)stat.mean;phys.abundfloatnullable<Abd9>? The average [X/Fe] abundance for Star 450log(Sun)stat.mean;phys.abundfloatnullable<Abd10>? The average [X/Fe] abundance for Star 472log(Sun)stat.mean;phys.abundfloatnullable<Abd11>? The average [X/Fe] abundance for Star 481log(Sun)stat.mean;phys.abundfloatnullable<Abd12>? The average [X/Fe] abundance for Star 36log(Sun)stat.mean;phys.abundfloatnullable<Abd13>? The average [X/Fe] abundance for Star 47log(Sun)stat.mean;phys.abundfloatnullable<Abd14>? The average [X/Fe] abundance for Star 202log(Sun)stat.mean;phys.abundfloatnullable<Abd15>? The average [X/Fe] abundance for Star 334log(Sun)stat.mean;phys.abundfloatnullable<Abd16>? The average [X/Fe] abundance for Star 403log(Sun)stat.mean;phys.abundfloatnullable<Abd17>? The average [X/Fe] abundance for Star 454log(Sun)stat.mean;phys.abundfloatnullable<Abd18>? The average [X/Fe] abundance for Star 458log(Sun)stat.mean;phys.abundfloatnullable<Abd19>? The average [X/Fe] abundance for Star 533log(Sun)stat.mean;phys.abundfloatnullable<Abd20>? The average [X/Fe] abundance for Star 547log(Sun)stat.mean;phys.abundfloatnullable<Abd21>? The average [X/Fe] abundance for Star 170log(Sun)stat.mean;phys.abundfloatnullable<Abd22>? The average [X/Fe] abundance for Star 289log(Sun)stat.mean;phys.abundfloatnullable<Abd23>? The average [X/Fe] abundance for Star 324log(Sun)stat.mean;phys.abundfloatnullable<Abd24>? The average [X/Fe] abundance for Star 337log(Sun)stat.mean;phys.abundfloatnullable<Abd25>? The average [X/Fe] abundance for Star 391log(Sun)stat.mean;phys.abundfloatnullableJ/AJ/149/204/refsReferencesRef[1/19] Reference identifierpos.frameintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintBibCodeBibliographic codemeta.bib.bibcodecharAutAuthor's namemeta.bib.authorcharCatCatalog identifier in VizieR databasemeta.id;meta.dataset;meta.tablechar