J/ApJ/882/27ivo://CDS.VizieR/J/ApJ/882/27doi:10.26093/cds/vizier.18820027CDSMardini M.K.Placco V.M.Taani A.Li H.Zhao G.2021-09-10T14:19:04Z2021-03-01T08:38:47ZCDS support team

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

cds-question@unistra.frmilky-way-galaxyhalo-starsline-intensitieschemically-peculiar-starsradial-velocitychemical-abundancesIn this work, we study the chemical compositions and kinematic properties of six metal-poor stars with [Fe/H]{<}-2.5 in the Galactic halo. From high-resolution (R~110000) spectroscopic observations obtained with the Lick/Automated Planet Finder, we determined individual abundances for up to 23 elements, to quantitatively evaluate our sample. We identify two carbon-enhanced metal-poor stars (J1630+0953 and J2216+0246) without enhancement in neutron-capture elements (CEMP-no stars), while the rest of our sample stars are carbon-intermediate. By comparing the light-element abundances of the CEMP stars with predicted yields from nonrotating zero-metallicity massive-star models, we find that the possible progenitors of J1630+0953 and J2216+0246 could be in the 13-25M_{sun}_ mass range, with explosion energies (0.3-1.8)x10^51^erg. In addition, the detectable abundance ratios of light and heavy elements suggest that our sample stars are likely formed from a well-mixed gas cloud, which is consistent with previous studies. We also present a kinematic analysis, which suggests that most of our program stars likely belong to the inner-halo population, with orbits passing as close as ~2.9kpc from the Galactic center. We discuss the implications of these results on the critical constraints on the origin and evolution of CEMP stars, as well as the nature of the Population III progenitors of the lowest-metallicity stars in our Galaxy.2019ApJ...882...27Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/882/27CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/A+A/305/245 : Fe I in metal-poor stars (Magain+, 1996)J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)J/ApJ/696/797 : Evolution and yields of low-mass AGB stars (Cristallo+, 2009)J/ApJS/182/80 : Rare earth abundances (Sneden+, 2009)J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)J/MNRAS/418/284 : s-process in low-metallicity stars. II. (Bisterzo+, 2011)J/ApJ/742/54 : CASH project II. Extremely metal-poor stars (Hollek+, 2011)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/AJ/145/13 : Metal-poor stars from SDSS/SEGUE. I. Abundances (Aoki+, 2013)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/ApJ/773/33 : Metal-poor subgiant BD+44 493 abundances (Ito+, 2013)J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)J/ApJ/788/180 : Metal-poor stars in the Milky Way's halo (Carollo+, 2014)J/MNRAS/444/392 : Synthetic Stellar Photometry. I. (Casagrande+, 2014)J/ApJ/797/21 : Carbon-enhanced metal-poor stars (Placco+, 2014)J/ApJ/833/20 : Carbon-enhanced metal-poor star abundances (Yoon+, 2016)J/ApJ/835/81 : Bright metal-poor stars from HES Survey. II. (Beers+, 2017)J/A+A/604/A129 : Formation of MW halo and its satellites (Mashonkina+, 2017)J/A+A/614/A68 : Carbon-enhanced metal-poor stars sample (Caffau+, 2018)J/ApJ/857/46 : Modelled vs observed abund. of EMP stars (Ishigaki+, 2018)J/ApJS/238/16 : LAMOST-DR3 very metal-poor star catalog (Li+, 2018)J/ApJ/875/89 : Metal-poor stars with APF. I. EMP stars (Mardini+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/882/27https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/882/27http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/882/27https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/882/27https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/882/27http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/882/27GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/882/27/stars (Lick/APF observations (Table 1) and stellar parameters of the program stars (Table 3))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/882/27/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/882/27/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/882/27/stars?GETtext/xml+votable180.050000true51.72452.04113890.0055555555555555566/8764 10771 19061 23220 28391 31680https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/882/27?format=asciidefaultJ/ApJ/882/27/starsLick/APF observations (Table 1) and stellar parameters of the program stars (Table 3)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/6] Running sequence numbermeta.idintIDIdentifier (JHHMM+DDMM)meta.id;meta.maincharprimaryDateDate of observation (UT)time.epochnullableRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainrmag[11.5/13] r-band magnitudemagphot.mag;em.opt.RfloatExpExposure timestime.duration;obs.exposurecharS/N[30/45] Signal-to-noise ratio (1)pixel**-1stat.snrintRV[-114.7/284.1] Radial velocity (2)km/sphys.veloc;pos.heliocentricfloatTeff[4783/5215] Lick/APF (corrected & adopted) effective temperatureKphys.temperature.effectiveintlogg[1.02/2.05] Lick/APF (corrected & adopted) log of surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H][-3.11/-2.52] Lick/APF (corrected & adopted) [Fe/H] abundancephys.abund.FefloatVt[1.08/2.37] Lick/APF (corrected & adopted) microturbulent velocitykm/sphys.velocfloatTeffS[4570/5050] Lick/APF (spectroscopic) effective temperatureKphys.temperature.effectiveintloggS[0.4/1.59] Lick/APF (spectroscopic) log of surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H]S[-3.26/-2.67] Lick/APF (spectroscopic) [Fe/H] abundancephys.abund.FefloatVtS[1.09/2.3] Lick/APF (spectroscopic) microturbulent velocitykm/sphys.velocfloatTeffp1[4693/5136] Photometric effective temperature from (V-J)Kphys.temperature.effectiveintTeffp2[4704/5187] Photometric effective temperature from (V-K)Kphys.temperature.effectiveintloggDR2[1.23/2.15] Log of surface gravity from Gaia DR2log(cm.s**-2)phys.gravityfloatGaiaGaia DR2 ID from Table 6 (column added by CDS)meta.id.crossEWsDisplay the equivalent width measurements for this star (link to Table 2)meta.ref.urlcharLAMOSTDisplay the LAMOST -DR4 (V/153) and -DR5 (V/164) data within 0.5"meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/ApJ/882/27/table2Equivalent widths of our samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[4023/6717.7] Wavelength; in Angstroms units (1)0.1nmem.wlfloatIonSpecies identifier (1)phys.atmol.ionStagecharExPot[0/4.65] Excitation potentialeVphys.atmol.excitationfloatlog(gf)[-5.7/0.6] log oscillator strengthphys.atmol.oscStrengthfloatEW1[1/122]? J0326+0202 equivalent width; in m{AA} units0.1pmmeta.unit;spect.line.eqWidthfloatnullableEW2[1.6/133]? J1108+2530 equivalent width; in m{AA} units0.1pmmeta.unit;spect.line.eqWidthfloatnullableEW3[1/147]? J1256+3440 equivalent width; in m{AA} units0.1pmmeta.unit;spect.line.eqWidthfloatnullableEW4[1/179]? J1413+1727 equivalent width; in m{AA} units0.1pmmeta.unit;spect.line.eqWidthfloatnullableEW5[1/144]? J1630+0953 equivalent width; in m{AA} units0.1pmmeta.unit;spect.line.eqWidthfloatnullableEW6[1/142.3]? J2216+0246 equivalent width; in m{AA} units0.1pmmeta.unit;spect.line.eqWidthfloatnullable