J/ApJ/812/109ivo://CDS.VizieR/J/ApJ/812/109doi:10.26093/cds/vizier.18120109CDSPlacco V.M.Beers T.C.Ivans I.I.Filler D.Imig J.A.Roederer I.U.,Abate C.Hansen T.Cowan J.J.Frebel A.Lawler J.E.Schatz H.,Sneden C.Sobeck J.S.Aoki W.Smith V.V.Bolte M.2017-01-23T22:00:00Z2016-02-25T16:24:40ZCDS support team

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

cds-question@unistra.frchemical-abundanceshalo-starschemically-peculiar-starsspectroscopyultraviolet-astronomyWe present an elemental-abundance analysis, in the near-ultraviolet (NUV) spectral range, for the bright carbon-enhanced metal-poor (CEMP) stars HD 196944 (V=8.40, [Fe/H]=-2.41) and HD 201626 (V=8.16, [Fe/H]=-1.51), based on data acquired with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope. Both of these stars belong to the sub-class CEMP-s, and exhibit clear over-abundances of heavy elements associated with production by the slow neutron-capture process. HD 196944 has been well-studied in the optical region, but we add abundance results for six species (Ge, Nb, Mo, Lu, Pt, and Au) that are only accessible in the NUV. In addition, we provide the first determination of its orbital period, P=1325 days. HD 201626 has only a limited number of abundance results based on previous optical work --here we add five new species from the NUV, including Pb. We compare these results with models of binary-system evolution and s-process element production in stars on the asymptotic giant branch, with the goal of explaining their origin and evolution. Our best-fitting models for HD 196944 (M_1,i_=0.9M_{sun}_, M_2,i_=0.86M_{sun}_, for [Fe/H]=-2.2), and HD 201626 (M_1,i_=0.9M_{sun}_, M_2,i_=0.76M_{sun}_ for [Fe/H]=-2.2; M_1,i_=1.6M_{sun}_, M_2,i_=0.59M_{sun}_ for [Fe/H]=-1.5) are consistent with the current accepted scenario for the formation of CEMP-s stars.2015ApJ...812..109Phttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/812/109CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)J/A+A/581/A22 : 67 CEMP-s stars model analysis (Abate+, 2015)J/ApJS/216/2 : MnI hyperfine lines in 1.4-1.8um (H) band (Andersson+, 2015)J/ApJS/215/20 : Vanadium log(gf) & transition probabilities (Lawler+, 2014)J/ApJS/214/26 : Line lists for CN isotopes transitions (Sneden+, 2014)J/ApJS/214/18 : VII log(gf) values, and V abundance in HD 84937 (Wood+ 2014)J/MNRAS/441/3127 : FeI oscillator strengths for Gaia-ESO (Ruffoni+, 2014)J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)J/MNRAS/440/1095 : Chemical analysis of CH stars (Karinkuzhi+, 2014)J/ApJS/211/20 : NiI transition probability measurements (Wood+, 2014)J/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)J/ApJ/764/78 : Oxygen abundances in nearby FGK stars (Ramirez+, 2013)J/ApJ/762/26 : Most metal-poor stars II. Galactic halo stars (Yong+, 2013)J/A+A/548/A34 : Carbon-enhanced metal-poor stars abundances (Allen+, 2012)J/MNRAS/427/343 : Infrared excesses of Hipparcos stars (McDonald+, 2012)J/MNRAS/418/284 : s-process in low-metallicity stars. II. (Bisterzo+, 2011)J/MNRAS/412/843 : SAGA extremely metal-poor stars (Suda+, 2011)J/ApJS/194/35 : Atomic transition probabilities of Mn (Den Hartog+, 2011)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)J/A+A/509/A93 : Carbon-enhanced metal-poor stars (Masseron+, 2010)J/ApJ/724/975 : Abundances of metal-poor stars (Roederer+, 2010)J/MNRAS/404/1529 : s-process in low-metallicity stars (Bisterzo+, 2010)J/MNRAS/403/1413 : Updated stellar yields from AGB models (Karakas, 2010)J/AJ/139/1051 : Carbon-enhanced metal-poor stars in the MW (Placco+, 2010)J/ApJ/658/1203 : Nitrogen-enhanced metal-poor stars (Johnson+, 2007)J/ApJ/658/367 : Abundances of carbon stars in Galactic halo (Komiya+, 2007)J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)J/ApJS/169/120 : Transition probabilities for HfII and Hf (Lawler+, 2007)J/A+A/402/343 : [OI] lines in F-K dwarfs/giants (Takeda, 2003)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/812/109https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/812/109http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/812/109https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/812/109https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/812/109http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/812/109GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapUVOpticaldefaultJ/ApJ/812/109/table2Derived optical abundance estimatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTypeAnalysis type (1)meta.notecharIonIon or molecule identifierphys.atmol.ionStagecharlambda[3360/7970.4] Wavelength in Angstroms0.1nmem.wlfloatchi[0/8.6]? Excitation potentialeVphys.atmol.excitationfloatnullablelog(gf)[-9.8/0.7]? Log oscillator strengthphys.atmol.oscStrengthfloatnullablel_HD196944Limit flag on HD196944meta.code.errorcharHD196944[-2/7.1]? Log number abundance of Ion in HD 196944meta.id;meta.mainfloatnullableHD201626[-0.04/8.6]? Log number abundance of Ion in HD 201626meta.idfloatnullable