J/A+A/621/A108ivo://CDS.VizieR/J/A+A/621/A108doi:10.26093/cds/vizier.36210108CDSArentsen A.Starkenburg E.ShetroneM.D.VennK.A.Depagne E.,McConnachie A.W.,2019-02-01T10:59:02Z2019-01-17T08:48:27ZCDS support team

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

cds-question@unistra.frpeculiar-variable-starsspectroscopic-binary-starsCarbon-enhanced metal-poor (CEMP) stars comprise a high percentage of stars at the lowest metallicities. The stars in the CEMP-no subcategory do not show any s-process enhancement and therefore cannot easily be explained by transfer of carbon and s-process elements from a binary AGB companion. We have performed radial velocity monitoring of a sample of 22 CEMP-no stars to further study the role that binarity plays in this type of CEMP star. We find four new binary CEMP-no stars based on their radial velocity variations; this significantly enlarges the population of known binaries to a total of 11. One of the new stars found to be in a binary system is HE 0107-5240, which is one of the most iron-poor stars known. This supports the binary transfer model for the origin of the abundance pattern of this star.We find a difference in binary fraction in our sample that depends on the absolute carbon abundance, with a binary fraction of 47 (+15/-14) % for stars with a higher absolute carbon abundance and 18 (+14/-9) % for stars with a lower absolute carbon abundance. This might imply a relation between a high carbon abundance and the binarity of a metal-poor star. Although binarity does not equate to mass transfer, there is a possibility that a CEMP-no star in a binary system has been polluted, and care has to be taken in the interpretation of their abundance patterns. We furthermore demonstrate the potential of Gaia of discovering additional binary candidates.2019A&A...621A.108Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/621/A108CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/490/769 : Yields from extremely metal-poor stars (Campbell+, 2008)J/ApJ/788/180 : Very metal-poor stars in the Milky Way's halo (Carollo+, 2014)J/A+A/574/A129 : The First CEMP star in the Sculptor dSph (Skuladottir+, 2015)J/A+A/579/A28 : Abundances of 3 CEMP stars (Bonifacio+, 2015)J/A+A/581/A22 : 67 CEMP-s stars model analysis (Abate+, 2015)J/ApJ/812/109 : HST + Keck spectroscopy of bright CEMP-s stars (Placco+, 2015)J/ApJ/814/121 : CASH project. III. The CEMP star HE0414-0343 (Hollek+, 2015)J/ApJ/833/20 : Carbon-enhanced metal-poor (CEMP) star abundances (Yoon+ 2016)J/A+A/586/A158 : Binary properties of CH and CEMP stars (Jorissen+, 2016)J/A+A/606/A55 : Rotational mixing in CEMP-s stars (Matrozis+, 2017)J/ApJS/228/19 : Exploring the SDSS data set. I. EMP + CV stars (Carbon+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/621/A108https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/621/A108http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/621/A108https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/621/A108https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/621/A108http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/621/A108GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/621/A108/tableb1 (List of 45 CEMP-no stars with multiple radial velocity measurements)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/621/A108/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/621/A108/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/621/A108/tableb1?GETtext/xml+votable180.050000true36.707245344.96292390.0055555555555555566/2067 2426 4419 10147 10430 11029 16795 16819 16854 16935 17095 17392 18608 18683 18719 22719 23199 25357 25534 25574 25733 25743 25785 25891 25963 26025 26057 26200 26232 26658 27319 31394 31595 32553 33192 34069 34844 35009 36548 44016 45345 45904 45913 46614 48234https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/621/A108?format=asciidefaultJ/A+A/621/A108/tableb1List of 45 CEMP-no stars with multiple radial velocity measurementsSimbadNameSimbad column added by the CDSmeta.idcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name (1)meta.id;meta.maincharo_RVNumber of radial velocity measurements in table C2 (full compilation)meta.numberintRVwWeighted average of o_RV radial velocitieskm/sphys.veloc;pos.heliocentricfloats_RVStandard deviation of o_RV radial velocitieskm/sstat.stdev;spect.dopplerVelocfloatl_P(chi2)Limit flag on P(chi2)meta.code.errorcharP(chi2)? Reduced chi square probability (p-value)stat.fit.goodnessdoublenullableBinBinary flag (2)meta.codecharTeffEffective temperatureKphys.temperature.effectiveintloggSurface gravityphys.gravityfloatl_[Fe/H]Limit flag on [Fe/H]meta.code.error;phys.abund.Fechar[Fe/H]? Iron abundancephys.abund.Fefloatnullablel_[C/Fe]Limit flag on [C/Fe]meta.code.error;phys.abundchar[C/Fe]Carbon to iron ratio (3)phys.abundfloatA(C)Absolute carbon abundance (3)phys.abundfloatl_[Ba/Fe]Limit flag on [Ba/Fe]meta.code.error;phys.abundchar[Ba/Fe]? Barium to iron ratiophys.abund.Fe;arith.ratiofloatnullable[Mg/C]? Magnesium to carbon ratio (3)phys.abundfloatnullableRefReference for stellar parameters (4)meta.ref;pos.frameintVCShow the Radial Velocity curvemeta.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/A+A/621/A108/tableb2*Compilation of 710 radial velocity measurements for 45 CEMP-no starsNameStar namemeta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHRVHeliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricdoubleHRV2? Second heliocentric radial velocity for SDSS 0929+0238 (1)km/sspect.dopplerVeloc;pos.heliocentricfloatnullableHRV3? Third heliocentric radial velocity for SDSS 0929+0238 (1)km/sspect.dopplerVeloc;pos.heliocentricfloatnullablee_HRV? Radial velocity uncertaintykm/sstat.errorfloatnullableHJDHeliocentric Julian date (HJD-2450000)dtime.epochdoubler_RVReference(s)meta.ref;pos.framechar