J/ApJ/801/125ivo://CDS.VizieR/J/ApJ/801/125doi:10.26093/cds/vizier.18010125CDSKirby E.N.Guo M.Zhang A.J.Deng M.Cohen J.G.Guhathakurta P.,Shetrone M.D.Lee Y.S.Rizzi L.2018-01-04T08:21:47Z2015-08-07T11:39:32ZCDS support team

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

cds-question@unistra.frchemical-abundancescarbon-starsgiant-starsspectroscopyWe present carbon abundances of red giants in Milky Way (MW) globular clusters and dwarf spheroidal galaxies (dSphs). Our sample includes measurements of carbon abundances for 154 giants in the clusters NGC2419, M68, and M15 and 398 giants in the dSphs Sculptor, Fornax, Ursa Minor, and Draco. This sample doubles the number of dSph stars with measurements of [C/Fe]. The [C/Fe] ratio in the clusters decreases with increasing luminosity above (L/L_{sun}_)~=1.6, which can be explained by deep mixing in evolved giants. The same decrease is observed in dSphs, but the initial [C/Fe] of the dSph giants is not uniform. Stars in dSphs at lower metallicities have larger [C/Fe] ratios. We hypothesize that [C/Fe] (corrected to the initial carbon abundance) declines with increasing [Fe/H] due to the metallicity dependence of the carbon yield of asymptotic giant branch stars and due to the increasing importance of SNe Ia at higher metallicities. We also identified 11 very carbon-rich giants (eight previously known) in three dSphs. However, our selection biases preclude a detailed comparison to the carbon-enhanced fraction of the MW stellar halo. Nonetheless, the stars with [C/Fe]<+1 in dSphs follow a different [C/Fe] track with [Fe/H] than the halo stars. Specifically, [C/Fe] in dSphs begins to decline at lower [Fe/H] than in the halo. The difference in the metallicity of the [C/Fe] "knee" adds to the evidence from [{alpha}/Fe] distributions that the progenitors of the halo had a shorter timescale for chemical enrichment than the surviving dSphs.2015ApJ...801..125Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/801/125CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/202 : Globular Clusters in the Milky Way (Harris, 1997)J/A+A/572/A88 : Measured EWs for Fornax RGB stars (Lemasle+, 2014)J/A+A/571/A47 : Extensive linelist of CH in atmospheres (Masseron+, 2014)J/MNRAS/440/1095 : Chemical analysis of CH stars (Karinkuzhi+, 2014)J/ApJ/762/27 : Most metal-poor stars. III. [Fe/H]<=-3.0 stars (Yong+, 2013)J/ApJ/760/86 : Equivalent widths for 13 NGC2419 RGB stars (Cohen+, 2012)J/A+A/544/A73 : BVI photometry of Fornax dSph galaxy (de Boer+, 2012)J/ApJ/740/60 : EWs for NGC2419 and NGC7099 RGB stars (Cohen+, 2011)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/ApJS/191/352 : Abundances in stars of MW dwarf satellites (Kirby+, 2010)J/ApJ/719/931 : Chemical evolution of the UMi dSph (Cohen+, 2010)J/MNRAS/403/1413 : Updated stellar yields from AGB models (Karakas, 2010)J/ApJ/705/328 : Abundance measurements in Sculptor dSph (Kirby+, 2009)J/ApJ/701/1053 : Abundances of 8 stars in the Draco dSph (Cohen+, 2009)J/ApJ/682/1217 : Abundances in red giants in 7 GCs (Kirby+, 2008)J/AJ/135/1993 : JHK mag of Sculptor dSph RR Lyrae (Pietrzynski+, 2008)J/MNRAS/375/831 : Draco MegaCam, INT and HST photometry (Segall+, 2007)J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)J/ApJ/652/1585 : Bright metal-poor stars from HES survey (Frebel+, 2006)J/A+A/459/423 : VI and [Fe/H] of Fornax dSph RGB stars (Battaglia+, 2006)J/AJ/132/137 : Extremely metal-poor carbon stars abundances (Cohen+, 2006)J/AJ/131/375 : Photometry & vel. of Sculptor dSph giants (Westfall+, 2006)J/AJ/128/1177 : Galactic stellar abundances (Venn+, 2004)J/AJ/124/3222 : VI photometry of Draco and UMi galaxies (Bellazzini+, 2002)J/A+A/354/169 : Metal-poor field stars abundances (Gratton+, 2000)J/PASP/110/533 : BR photometry of Fornax bright stars (Stetson+ 1998)J/AJ/110/2131 : M/L for Draco and UMi. I. (Armandroff+ 1995)J/AJ/108/555 : BVI photometry in globular cluster M68 (Walker, 1994)J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)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/ApJ/801/125https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/801/125http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/801/125https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/801/125https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/801/125http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/801/125GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/801/125/table1 (DEIMOS observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/801/125/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/801/125/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/801/125/table1?GETtext/xml+votable180.050000true114.535458338.88191670.005555555555555556Cone search capability for table J/ApJ/801/125/table4 (Carbon Abundances)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/801/125/table4?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/801/125/table4?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/801/125/table4?GETtext/xml+votable180.050000true114.473666738.85833330.0055555555555555566/6389 10183 11691 12405 24843 35549 35720 35969https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/801/125?format=asciiOpticaldefaultJ/ApJ/801/125/table1DEIMOS observationsSimbadNameSimbad column added by the CDSmeta.idcharSlitSlitmask identifiermeta.notecharNt[86/169]? Targets numbermeta.idintnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSystGlobular cluster or dwarf galaxymeta.id;meta.maincharprimaryNsNumber of red giants for this systemmeta.numberintnullableDateObservation datetime.epoch;obsnullableAirM[1/1.9] Airmassobs.airMassfloatSeeing[0.6/1.3] Seeingarcsecinstr.obsty.seeingfloatExposuresIndividual exposure time(s)stime.duration;obs.exposurechartExp[1800/6360]? Total exposure timestime.duration;obs.exposureintnullableNEDSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/ApJ/801/125/table2LinelistA[12/13]? Isotope of carbonphys.atmol.weightintnullablelog(gf)[-9/1.5] Logarithm of oscillator strengthphys.atmol.oscStrengthfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[4100/4500] Air wavelength0.1nmem.wldoubleElName of atom or moleculemeta.id;meta.maincharIon? Ionization state of atomphys.atmol.ionStagecharEP[0/38.3] Excitation potentialeVphys.atmol.excitationfloatJ/ApJ/801/125/table4Carbon Abundancesmag3[11/21.3]? Extinction-corrected magnitude in Filt3magphot.magfloatnullablelogL[0.6/3.6] Log of luminosity relative to sunlog(solLum)phys.luminosityfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSystGlobular cluster or dwarf galaxy (1)meta.id.parentcharNameObject namemeta.id;meta.maincharRAJ2000Hour of Right Ascension (J2000) (4)pos.eq.ra;meta.mainDEJ2000Sign of the Declination (J2000) (4)pos.eq.dec;meta.mainn_mag1[Bg]? First filter (B or g)meta.code;instr.filtercharmag1[13.4/22]? Extinction-corrected magnitude in Filt1magphot.magfloatnullablen_mag2[MRVr] Second filter (M, V, R or r)meta.code;instr.filtercharmag2[12/22] Extinction-corrected magnitude in Filt2magphot.magfloatn_mag3[ITi]? Third filter (T, I or i)meta.code;instr.filtercharS/N[0/225]? Spectral signal-to-noise ratio per Angstromnm**-1stat.snrfloatnullableTeff[3743/5966]? Effective temperatureKphys.temperature.effectiveintnullablelog(g)[0.1/3.6]? Surface gravitylog(cm.s**-2)phys.gravityfloatnullable[Fe/H][-3.3/-0.4]? Iron abundance relative to the Sunlog(Sun)phys.abund.Fefloatnullablee_[Fe/H][0.1/0.4]? Uncertainty in [Fe/H]log(Sun)stat.error;phys.abund.Fefloatnullable[a/Fe][-0.8/1.2]? [{alpha}/Fe], {alpha}-to-iron ratio relative to the Sunlog(Sun)phys.abundfloatnullablee_[a/Fe][0.01/1]? Uncertainty in [a/Fe]log(Sun)stat.error;phys.abundfloatnullablel_[C/Fe]? Upper limit flag for [C/Fe]meta.code.error;phys.abundchar[C/Fe][-1.6/1.1]? Carbon-to-iron ratio relative to the Sunlog(Sun)phys.abundfloatnullablee_[C/Fe][0.1/0.4]? Uncertainty in [C/Fe]log(Sun)stat.error;phys.abundfloatnullablel_[C/Fe]c? Upper limit flag for [C/Fe]cmeta.code.error;phys.abundchar[C/Fe]c[-1.3/1.1]? [C/Fe] corrected for evolutionary state (2)log(Sun)phys.abundfloatnullableS2CH[0.2/2.4]? S_2_(CH) index (3)magspect.indexfloatnullablee_S2CH[0/0.51]? Uncertainty in S2(CH)magstat.errorfloatnullableC[C] "C" indicates a Carbon starsrc.classchar