J/A+A/674/A180ivo://CDS.VizieR/J/A+A/674/A180doi:10.26093/cds/vizier.36740180CDSHansen T.T.Simon J.D.Li T.S.Frebel A.Thompson I.Shectman S.2024-11-28T20:03:44Z2023-06-19T08:49:08ZCDS support team

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

cds-question@unistra.frgalaxieschemically-peculiar-starschemical-abundancesline-intensitiesvisible-astronomyCarbon Enhanced Metal-Poor (CEMP) stars ([C/Fe]>0.7) are known to exist in large numbers at low metallicity in the Milky Way halo and are important tracers of early Galactic chemical evolution. However, very few such stars have been identified in the classical dwarf spheroidal (dSph) galaxies, and detailed abundances, including neutron-capture element abundances, have only been reported for 13 stars. We aim to derive detailed abundances of six CEMP stars identified in the Carina dSph and compare the abundances to CEMP stars in other dSph galaxies and the Milky Way halo. This is the largest sample of CEMP stars in a dSph galaxy analysed to date. Methods. 1D LTE elemental abundances are derived via equivalent width and spectral synthesis using high-resolution spectra of the six stars obtained with the MIKE spectrograph at Las Campanas Observatory. Abundances or upper limits are derived for up to 27 elements from C to Os in the six stars. The analysis reveals one of the stars to be a CEMP-no star with very low neutron-capture element abundances. In contrast, the other five stars all show enhancements in neutron-capture elements in addition to their carbon enhancement, classifying them as CEMP-s and -r/s stars. The six stars have similar {alpha} and iron-peak element abundances as other stars in Carina, except for the CEMP-no star, which shows enhancement in Na, Mg, and Si. We explore the absolute carbon abundances (A(C)) of CEMP stars in dSph galaxies and find similar behaviour as is seen for Milky Way halo CEMP stars, but highlight that CEMP-r/s stars primarily have very high A(C) values. We also compare the neutron-capture element abundances of the CEMP-r/s stars in our sample to recent i-process yields, which provide a good match to the derived abundances.2023A&A...674A.180Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/674/A180CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/674/A180https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/674/A180http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/674/A180https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/674/A180https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/674/A180http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/674/A180GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/674/A180/table1 (Observation Log for MIKE Data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/674/A180/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/674/A180/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/674/A180/table1?GETtext/xml+votable180.050000true100.28575-50.797250.0055555555555555566/39097 39100https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/674/A180?format=asciiOpticaldefaultJ/A+A/674/A180/table1Observation Log for MIKE DataDEJ2000Declination (J2000)pos.eq.dec;meta.mainSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar ID ([FBN2016] NNNNNN in Simbad)meta.id;meta.mainintRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainExpTimeTotal exposure timetime.duration;obs.exposurecharSN-4500SN@4500{AA}stat.snrintSN-6500SN@6500{AA}stat.snrintJ/A+A/674/A180/table6Abundance uncertaintiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar IDmeta.id;meta.mainintSpeciesSpecies identifiermeta.idcharDTeffUncertainty in loge(X) from effective temperaturestat.errorfloatDloggUncertainty in loge(X) from gravitystat.errorfloatDvtUncertainty in loge(X) from microturbulencestat.errorfloatD[Fe/H]Uncertainty in loge(X) from metallicitystat.errorfloate_loge(X)Statistical uncertainty in loge(X)stat.errorfloatJ/A+A/674/A180/tableb1Atomic data and abundances for individual lines analysedrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar IDmeta.id;meta.mainintWaveWavelength in Angstroms0.1nmem.wlfloatSpeciesSpecies identifiermeta.idfloatExPotExcitation PotentialeVphys.atmol.excitationfloatlog(gf)Log of oscillator strengthphys.atmol.oscStrengthfloatn_EW[s] s for synthmeta.notecharEW? Equivalenth width in mili angstroms0.1pmspect.line.widthfloatnullablen_e_EW[s] s for synthmeta.notechare_EW? Error on Equivalenth width in mili angstroms0.1pmstat.error;spect.line.eqWidthfloatnullableloge(X)Log epsilon abundance of element Xphys.abund.XfloatRefReference (1)meta.ref;pos.frameint