J/A+A/548/A34ivo://CDS.VizieR/J/A+A/548/A34doi:10.26093/cds/vizier.35480034CDSAllen D.M.Ryan S.G.Rossi S.Beers T.C.Tsangarides S.A.2018-06-13T12:01:40Z2012-11-30T12:40:21ZCDS support team

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

cds-question@unistra.frcarbon-starschemically-peculiar-starschemical-abundancesWe present a detailed study of Carbon-Enhanced Metal-Poor (CEMP) stars, based on high-resolution spectroscopic observations of a sample of 18 stars. The stellar spectra for this sample were obtained at the 4.2m William Herschel Telescope (WHT) in 2001 and 2002, using the Utrecht Echelle Spectrograph (UES), at a resolving power R~52000 and S/N~40, covering the wavelength range {lambda}-{lambda}3700-5700{AA}. The atmospheric parameters determined for this sample indicate temperatures ranging from 4750K to 7100K, log g from 1.5 to 4.3, and metallicities -3.0<=[Fe/H]<=-1.7. Elemental abundances for C, Na, Mg, Sc, Ti, Cr, Cu, Zn, Sr, Y, Zr, Ba, La, Ce, Nd, Sm, Eu, Gd, Dy are determined. Abundances for an additional 109 stars were taken from the literature and combined with the data of our sample. The literature sample reveals a lack of reliable abundance estimates for species that might be associated with the r-process elements for about 67% of CEMP stars, preventing a complete understanding of this class of stars, since [Ba/Eu] ratios are used to classify them. Although eight stars in our observed sample are also found in the literature sample, Eu abundances or limits are determined for four of these stars for the first time. From the observed correlations between C, Ba, and Eu, we argue that the CEMP-r/s class has the same astronomical origin as CEMP-s stars, highlighting the need for a more complete understanding of Eu production.2012A&A...548A..34Ahttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/548/A34CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/548/A34https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/548/A34http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/548/A34https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/548/A34https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/548/A34http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/548/A34GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/548/A34/table1 (Colours and magnitudes of our program stars before dereddening)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/548/A34/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/548/A34/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/548/A34/table1?GETtext/xml+votable180.050000true152.3987525.9922220.0055555555555555566/5249 9218 10002 10165 10249 10272 10340 10430 10682 11404 11482 11657 16603 17499 17543 17994 18483 18507 18683 18737 19484 28475 36228 36308 36426 44542 485557.952274030004205e-20 3.852589004194616e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/548/A34?format=asciidefaultJ/A+A/548/A34/table1Colours and magnitudes of our program stars before dereddeningrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSampleSubsample: DMA (Dinah M. Allen) or SAT (Stelios A. Tsangarides)meta.idcharStarStar namemeta.id;meta.maincharn_Star[*] position and magnitude added at CDS (concerns HD 140283)meta.notecharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainVmag? V magnitudemagphot.mag;em.opt.VfloatnullableE(B-V)? Interstellar reddeningmagphot.color.excessfloatnullableAV? Absorption in V bandmagphot.mag;em.opt.Vfloatnullablee_AV? rms uncertainty on AVmagstat.errorfloatnullableB-V? B-V colour indexmagphot.color;em.opt.B;em.opt.Vfloatnullablen_B-V[X] X for value not usedmeta.notecharV-R? V-R colour indexmagphot.color;em.opt.V;em.opt.RfloatnullableV-I? V-I colour indexmagphot.color;em.opt.V;em.opt.IfloatnullableJmag? J magnitudemagphot.mag;em.IR.Jfloatnullablee_Jmag? rms uncertainty on Jmagmagstat.error;phot.mag;em.IR.JfloatnullableHmag? H magnitudemagphot.mag;em.IR.Hfloatnullablee_Hmag? rms uncertainty on Hmagmagstat.error;phot.mag;em.IR.HfloatnullableKsmag? Ks magnitudemagphot.mag;em.IR.Kfloatnullablee_Ksmag? rms uncertainty on Ksmagmagstat.error;phot.mag;em.IR.KfloatnullableGLON? Galactic longitudedegpos.galactic.lonnullableGLAT? Galactic latitudedegpos.galactic.latfloatnullableS/N? Signal-to-noise ratio of the high-resolution spectra around {lambda}4500{AA}stat.snrintnullableNote? Notesmeta.notecharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/548/A34/table2Iron lines for DMA subsamplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharIonElement code and ionization statephys.atmol.ionStagecharlambdaWavelength of the line0.1nmem.wl;spect.linedoubleEPLower excitation potentialeVphys.atmol.excitation;stat.minfloatloggfLogarithm of oscillator strengthphys.atmol.oscStrengthfloatr_loggf[1/9] References for oscillator strength (1)meta.ref;pos.frameintl_EWUpper limit flag on EWmeta.code.error;spect.line.eqWidthcharEW? Equivalent width0.1pmspect.line.eqWidthfloatnullablen_EW[s] s indicates spectrum synthesismeta.notecharJ/A+A/548/A34/table5All abundances for SAT subsamplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharIonElement code and ionization statephys.atmol.ionStagecharlambdaWavelength of the line0.1nmem.wl;spect.linedoubleEPLower excitation potentialeVphys.atmol.excitation;stat.minfloatloggfLogarithm of oscillator strengthphys.atmol.oscStrengthfloatr_loggf[1/9] References for oscillator strength (1)meta.ref;pos.frameintl_EWUpper limit flag on EWmeta.code.error;spect.line.eqWidthcharEW? Equivalent width0.1pmspect.line.eqWidthfloatnullablen_EW[s] s indicates spectrum synthesismeta.notecharJ/A+A/548/A34/table7Other elemental abundances for DMA subsamplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarStar namemeta.id;meta.maincharIonElement code and ionization statephys.atmol.ionStagecharlambdaWavelength of the line0.1nmem.wl;spect.linecharEP? Lower excitation potentialeVphys.atmol.excitation;stat.minfloatnullableloggf? Logarithm of oscillator strengthphys.atmol.oscStrengthfloatnullabler_loggf? References for oscillator strength (1)meta.ref;pos.frameintnullableEW? Equivalent width for the star0.1pmspect.line.eqWidthintnullablen_EW[s] s indicates spectrum synthesismeta.notecharlogEps? Average of log{epsilon}= log(Nx/NH) + 12phys.abundfloatnullable[X/Fe]? Average of the overabundance of the element X relative to Fephys.abundfloatnullable