J/A+A/690/A333ivo://CDS.VizieR/J/A+A/690/A333doi:10.26093/cds/vizier.36900333CDSSestito F.Ardern-Arentsen A.Vitali S.Montelius M.Lucchesi R.,Venn K.A.Martin N.F.Navarro J.F.Starkenburg E.2026-08-31T14:15:59Z2024-10-22T10:52:02ZCDS support team

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

cds-question@unistra.frgalaxieschemically-peculiar-starschemical-abundancesvisible-astronomyradial-velocityeffective-temperatureWe aim to constrain the chemo-dynamical properties of the Sagittarius (Sgr) dwarf galaxy using carbon abundances. At low metallicities in particular, these properties reveal the early chemical evolution of a system, tracing the contributing supernovae (SNe) and how much of their ejecta eventually made it into the next stellar generation. Our sample from the Pristine Inner Galaxy Survey (PIGS) includes ~350 metal-poor ([Fe/H]<-1.5) stars in the main body of Sgr with good quality spectroscopic observations. Our metalpoor Sgr population has a larger velocity dispersion than metal-rich Sgr from the literature, which could be explained by outside-in star formation, extreme Galactic tidal perturbations, and/or the presence of a metal-rich disc and bar + metal-poor halo. The average carbon abundance [C/Fe] in Sgr is similar to that of other classical dwarf galaxies (DGs) and consistently lower than in the Milky Way by ~0.2-0.3dex at low metallicities. The interstellar medium in DGs, including Sgr, may have retained yields from more energetic Population III and II supernovae (SNe), thereby reducing the average [C/Fe]. Additionally, SNe Ia producing more Fe than C would start to contribute at lower metallicity in DGs/Sgr than in the Galaxy. The presence of a [C/Fe] gradient for Sgr stars with [Fe/H]>~-2.0 (~6.8x10^-4^dex/ arcmin) suggests that SNe Ia contributed to the system at those metallicities, especially in its inner regions. There is a low frequency of carbon-enhanced metal-poor (CEMP) stars in our Sgr sample. At higher metallicities and carbon abundances (i.e. mostly CEMPs), this may be due to photometric selection effects, but those are less likely to affect non-CEMP stars. Given the lower average [C/Fe] in DGs, we propose using the same CEMP definition ([C/Fe]>+0.7) as that applied to the Galaxy at large ends up underpredicting the number of CEMP stars in DGs. Burthermore, for Sgr, a cut at [C/Fe]~+0.35 may be more appropriate, which brings the frequency of CEMP stars in agreement with that of the whole Galaxy.2024A&A...690A.333Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/690/A333CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/355 : Gaia DR3 Part 1. Main source (Gaia Collaboration, 2022)J/MNRAS/530/3391 : Pristine Inner Galaxy Survey. VIII. (Ardern-Arentsen+, 2024)J/A+A/689/A201 : Pristine Inner Galaxy Survey. IX. (Sestito+, 2024)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/690/A333https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/690/A333http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/690/A333https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/690/A333https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/690/A333http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/690/A333GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/690/A333/memb (*Sgr members using a kinematical selection based on Gaia)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A333/memb?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A333/memb?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A333/memb?GETtext/xml+votable180.050000true286.20275-30.120944444440.005555555555555556Cone search capability for table J/A+A/690/A333/membpara (Sgr members from PIGS/AAT that have reliable measurements of metallicity, [C/Fe], and stellar parameters)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/690/A333/membpara?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/690/A333/membpara?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/690/A333/membpara?GETtext/xml+votable180.050000true281.19070833333-27.944472222220.0055555555555555565/11965 12003 12008 12010 6/28757 28928-28929 28931 47868-47869 47871 48011 48036-48038 48044https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/690/A333?format=asciiOpticaldefaultJ/A+A/690/A333/memb*Sgr members using a kinematical selection based on GaiarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordinte_TeffEffective temperature error from FERREKstat.error;phys.temperature.effectivedoubleloggSurface gravity from FERRElog(cm.s**-2)phys.gravityfloatSimbadSimbad column added by the CDSmeta.ref.urlcharFieldPIGS fieldname (FieldLLL.l+BB.b)obs.fieldcharGaiaDR3Gaia DR3 source IDmeta.idRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainRVRadial velocitykm/sphys.veloc;pos.heliocentricdoublee_RVRadial velocity errorkm/sstat.errorfloatTeffEffective temperature from FERREKphys.temperature.effectivedoublee_loggSurface gravity error from FERRElog(cm.s**-2)stat.errorfloat[Fe/H]Metallicity from FERREphys.abund.Zfloate_[Fe/H]Metallicity error from FERREstat.error;phys.abund.Fefloat[C/Fe]Abundance [C/Fe] from FERREphys.abundfloate_[C/Fe]Abundance [C/Fe] error from FERREstat.error;phys.abundfloat[C/Fe]corr? Correction to [C/Fe] as in Placco et al., 2014ApJ...797...21P, Cat. J/ApJ/797/21)arith.factorfloatnullablepmRAredReduced proper motion on right ascensionmas/yrpos.pm;pos.eq.radoublepmDEredReduced proper motion on declinationmas/yrpos.pm;pos.eq.decdoublePIGSStarname with PIGS nomenclature (Pristine_HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharJ/A+A/690/A333/membparaSgr members from PIGS/AAT that have reliable measurements of metallicity, [C/Fe], and stellar parametersSimbadSimbad column added by the CDSmeta.ref.urlcharFieldPIGS fieldname (FieldLLL.l+BB.b)obs.fieldcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintPIGSStarname with PIGS nomenclature (Pristine_HHMMSS.ss+DDMMSS.s)meta.id;meta.maincharGaiaDR3Gaia DR3 source IDmeta.idRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainRVRadial velocitykm/sphys.veloc;pos.heliocentricdoublee_RVRadial velocity errorkm/sstat.errorfloatTeffEffective temperature from FERREKphys.temperature.effectivedoublee_TeffEffective temperature error from FERREKstat.error;phys.temperature.effectivedoubleloggSurface gravity from FERRElog(cm.s**-2)phys.gravityfloate_loggSurface gravity error from FERRElog(cm.s**-2)stat.errorfloat[Fe/H]Metallicity from FERREphys.abund.Zfloate_[Fe/H]Metallicity error from FERREstat.error;phys.abund.Fefloat[C/Fe]Abundance [C/Fe] from FERREphys.abundfloate_[C/Fe]Abundance [C/Fe] error from FERREstat.error;phys.abundfloat[C/Fe]corr? Correction to [C/Fe] as in Placco et al., 2014ApJ...797...21P, Cat. J/ApJ/797/21)arith.factorfloatnullablepmRAredReduced proper motion on right ascensionmas/yrpos.pm;pos.eq.radoublepmDEredReduced proper motion on declinationmas/yrpos.pm;pos.eq.decdouble