J/ApJ/862/174ivo://CDS.VizieR/J/ApJ/862/174doi:10.26093/cds/vizier.18620174CDSGull M.Frebel A.Cain M.G.Placco V.M.Ji A.P.Abate C.Ezzeddine R.,Karakas A.I.Hansen T.T.Sakari C.Holmbeck E.M.Santucci R.M.,Casey A.R.Beers T.C.2020-02-14T06:14:23Z2019-08-29T11:45:56ZCDS support team

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

cds-question@unistra.frchemically-peculiar-starsgiant-starsline-intensitieschemical-abundancesradial-velocityvisible-astronomyWe present a high-resolution (R~35000), high signal-to-noise ratio (S/N>200) Magellan/MIKE spectrum of the star RAVE J094921.8-161722, a bright (V=11.3) metal-poor red giant star with [Fe/H]=-2.2, identified as a carbon-enhanced metal-poor (CEMP) star from the RAVE survey. We report its detailed chemical abundance signature of light fusion elements and heavy neutron-capture elements. We find J0949-1617 to be a CEMP star with s-process enhancement that must have formed from gas enriched by a prior r-process event. Light neutron-capture elements follow a low-metallicity s-process pattern, while the heavier neutron-capture elements above Eu follow an r-process pattern. The Pb abundance is high, in line with an s-process origin. Thorium is also detected, as expected from an r-process origin, as Th is not produced in the s-process. We employ nucleosynthesis model predictions that take an initial r-process enhancement into account, and then determine the mass transfer of carbon and s-process material from a putative more massive companion onto the observed star. The resulting abundances agree well with the observed pattern. We conclude that J0949-1617 is the first bonafide CEMP-r+s star identified. This class of objects has previously been suggested to explain stars with neutron-capture element patterns that originate from neither the r- nor the s-process alone. We speculate that J0949-1617 formed in an environment similar to those of ultra-faint dwarf galaxies like TucanaIII and ReticulumII, which were enriched in r-process elements by one or multiple neutron star mergers at the earliest times.2018ApJ...862..174Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/862/174CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/eso : ESO Science Archive Catalog (ESO, 1991-2019)III/279 : RAVE 5th data release (Kunder+, 2017)J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)J/MNRAS/403/1413 : Updated stellar yields from AGB models (Karakas, 2010)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/AJ/142/193 : RAVE stellar elemental abundances (DR1) (Boeche+, 2011)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)J/ApJ/794/58 : Metal-poor stars in the Galaxy thick disk (Beers+, 2014)J/A+A/569/A43 : HE 2252-4225 abundance analysis (Mashonkina+, 2014)J/A+A/571/A47 : Extensive linelist of CH in stellar atmospheresJ/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)J/A+A/581/A22 : 67 CEMP-s stars model analysis (Abate+, 2015)J/ApJ/830/93 : Abundances of Ret II brightest red giant members (Ji+, 2016)J/ApJ/821/37 : Abundances of metal-poor star HD 94028 (Roederer+, 2016)J/ApJ/847/142 : Ultra-metal-poor stars LTE & NLTE abund. (Ezzeddine+, 2017)J/ApJ/838/44 : Abundances of Tuc III brightest members (Hansen+, 2017)J/A+A/607/A91 : CS 29497-004 abundances (Hill+, 2017)J/A+A/608/A46 : Constraining cosmic scatter (Reggiani+, 2017)J/AJ/155/256 : Spectro. validation of RAVE metal-poor stars (Placco+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/862/174https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/862/174http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/862/174https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/862/174https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/862/174http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/862/174GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/862/174/table1Radial velocities of the CEMP-r+s star RAVE J094921.8-161722recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateUT date of observationtime.epoch;obsnullableHRV[389.5/392.5] Heliocentric radial velocity (1)km/sspect.dopplerVeloc;pos.heliocentricfloatObsObservatory/Survey (1)meta.notecharJ/ApJ/862/174/table2Line list of RAVE J094921.8-161722recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpecies identifierphys.atmol.ionStagecharlambda[3360/7511.1] Wavelength in Angstrom0.1nmem.wlfloatExPot[-0.6/5]? Excitation potentialeVphys.atmol.excitationfloatnullablelog(gf)[-10.3/3]? log oscillator strengthphys.atmol.oscStrengthfloatnullableEW[2.3/361.5]? Equivalent width in milli-Angstrom1e-13mspect.line.eqWidthfloatnullablef_EW[s] Indicates abundance was measured using a synthetic spectrummeta.codecharloge[-1.7/7.4] log absolute abundancephys.abundfloatJ/ApJ/862/174/table4Line list of the {lambda}4019 regionrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpecies identifierphys.atmol.ionStagelambda[4018/4020.6] Wavelength in Angstroms0.1nmem.wldoubleExPot[0/14.5] Excitation potentialeVphys.atmol.excitationfloatlog(gf)[-9.8/0.6] log oscillator strengthphys.atmol.oscStrengthfloat