J/ApJ/875/89ivo://CDS.VizieR/J/ApJ/875/89doi:10.26093/cds/vizier.18750089CDSMardini M.K.Li H.Placco V.M.Alexeeva S.Carollo D.Taani A.,Ablimit I.Wang L.Zhao G.2021-09-08T12:51:20Z2020-10-20T15:06:51ZCDS support team

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

cds-question@unistra.frchemically-peculiar-starsline-intensitiesvisible-astronomyspectroscopychemical-abundancesWe report on the discovery of five carbon-enhanced metal-poor (CEMP) stars in the metallicity range of -3.3<[Fe/H]{<}-2.4. These stars were selected from the LAMOST DR3 low-resolution (R~2000) spectroscopic database as metal-poor candidates and followed up with high-resolution spectroscopy (R~110000) with the Lick/APF. Stellar parameters and individual abundances for 25 chemical elements (from Li to Eu) are presented for the first time. These stars exhibit chemical abundance patterns that are similar to those reported in other literature studies of very and extremely metal-poor stars. One of our targets, J2114-0616, shows high enhancement in carbon ([C/Fe]=1.37), nitrogen ([N/Fe]=1.88), barium ([Ba/Fe]=1.00), and europium ([Eu/Fe]=0.84). Such chemical abundance pattern suggests that J2114-0616 can be classified as CEMP-r/s star. In addition, the star J1054+0528 can be classified as a CEMP-rI star, with [Eu/Fe]=0.44 and [Ba/Fe]=-0.52. The other stars in our sample show no enhancements in neutron-capture elements and can be classified as CEMP-no stars. We also performed a kinematic and dynamical analysis of the sample stars based on Gaia DR2 data. The kinematic parameters, orbits, and binding energy of these stars show that J2114-0616 is member of the outer-halo population, while the remaining stars belong to the inner-halo population but with an accreted origin. Collectively, these results add important constraints on the origin and evolution of CEMP stars as well as on their possible formation scenarios.2019ApJ...875...89Mhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/875/89CatalogResearchIsServedByTAP 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)V/153 : LAMOST DR4 catalogs (Luo+, 2018)J/A+A/354/169 : Metal-poor field stars abundances (Gratton+, 2000)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/658/1203 : Nitrogen-enhanced metal-poor stars (Johnson+, 2007)J/A+A/503/541 : Neutral Li in late-type stars (Lind+, 2009)J/A+A/509/A93 : Carbon-enhanced metal-poor stars (Masseron+, 2010)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/AJ/145/13 : Metal-poor stars from SDSS/SEGUE. I. (Aoki+, 2013)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/ApJ/773/33 : Analysis of the metal-poor subgiant BD+44 493 (Ito+, 2013)J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)J/ApJ/788/180 : Very metal-poor stars in the MW's halo (Carollo+, 2014)J/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/798/110 : Equivalent widths of LAMOST metal-poor stars (Li+, 2015)J/ApJ/812/109 : HST & Keck spectrosc. of bright CEMP-s stars (Placco+, 2015)J/ApJ/821/37 : Abundances of metal-poor star HD 94028 (Roederer+, 2016)J/MNRAS/456/1221 : FGK dwarfs atmospheric parameters (Ryabchikova+, 2016)J/ApJ/833/20 : Carbon-enhanced metal-poor (CEMP) star abund. (Yoon+, 2016)J/ApJ/833/225 : -2.6<=[Fe/H]<=0.2 F and G dwarfs. II. (Zhao+, 2016)J/A+A/604/A129 : The MW halo & its dwarf satellites (Mashonkina+, 2017)J/A+A/614/A68 : Carbon-enhanced metal-poor stars sample (Caffau+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/875/89https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/875/89http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/875/89https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/875/89https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/875/89http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/875/89GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/875/89/stars (Lick/APF observations (Table 1), stellar parameters (Table 3) and Gaia distances (Table 7) of the program stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/875/89/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/875/89/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/875/89/stars?GETtext/xml+votable180.050000true7.8204583-16.79466670.0055555555555555566/8274 9647 13344 16821 27456 49105https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/875/89?format=asciiOpticaldefaultJ/ApJ/875/89/starsLick/APF observations (Table 1), stellar parameters (Table 3) and Gaia distances (Table 7) of the program starsSimbadNameSimbad column added by the CDSmeta.idcharExpExposure timestime.duration;obs.exposureintIDStar identifiermeta.id;meta.mainchare_plx[0.02/0.07] plx uncertaintymasstat.error;pos.parallaxfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[1/6] Running sequence numbermeta.idintDateUT date of observationtime.epoch;obsnullableRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainrmag[8.5/12.8] r-band magnitudemagphot.mag;em.opt.Rfloato_ExpNumber of exposuresmeta.numberintS/N[40/47] Signal to noise ratio per pixel measured at {lambda}~4500{AA}pixel**-1stat.snr;instr.pixelintHRV[-339.4/82.4] Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatEWsDisplay the equivalent width measurements for this star (link to Table 2)meta.ref.urlcharTeff[4810/5085] Lick/APF (adopted) effective temperatureKphys.temperature.effectiveintlogg[1/2] Lick/APF (adopted) log of surface gravitylog(cm.s**-2)phys.gravityfloat[Fe/H][-3.3/-2.4] Lick/APF (adopted) metallicitylog(Sun)phys.abund.ZfloatVt[1.79/2.93] Lick/APF microturbulent velocity ({xi})km/sphys.velocfloatTeff2[4377/5094]? LAMOST effective temperatureKphys.temperature.effectiveintnullablelogg2[1.54/2.65]? LAMOST log of surface gravitylog(cm.s**-2)phys.gravityfloatnullable[Fe/H]2[-3.3/-2.9]? LAMOST metallicitylog(Sun)phys.abund.ZfloatnullableTeff3[4870/5080] Gaia DR2 effective temperatureKphys.temperature.effectiveintlogg3[1.39/2.15] Gaia DR2 log of surface gravity (1)log(cm.s**-2)phys.gravityfloatTeffp[4652/4981]? Photometric effective temperatureKphys.temperature.effectiveintnullablelogL[132/1014] Log of luminosity in erg/slog(1e-07W)phys.luminosityfloatGaiaGaia DR2 identifiermeta.id.crossplx[0.045/1.5] Gaia DR2 (I/345) parallaxmaspos.parallax.trigfloatpmRA[-20.5/0.4] Gaia DR2 proper motion in RAmas/yrpos.pm;pos.eq.rafloate_pmRA[0.03/0.2] pmRA uncertaintymas/yrstat.error;pos.pm;pos.eq.rafloatpmDE[-51.1/-1.4] Gaia DR2 proper motion in DECmas/yrpos.pm;pos.eq.decfloate_pmDE[0.04/0.09] pmDE uncertaintymas/yrstat.error;pos.pm;pos.eq.decfloatDist[0.66/8.4] Gaia distance from Bailer-Jones+, 2018, I/347kpcpos.distance;pos.heliocentricfloate_Dist[0.027/1] 16th percentile confidence interval on Distkpcstat.errorfloatE_Dist[0.028/1.3] 84th percentile confidence interval on Distkpcstat.error;stat.maxfloatJ/ApJ/875/89/table2Equivalent widths of our samplerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[4023/6970] Wavelength, Angstroms1e-10mem.wlfloatIonIon identifierphys.atmol.ionStagecharExPot[0/4.35]? Excitation potential, {Chi}eVphys.atmol.excitationfloatnullablelog(gf)[-4.95/0.61]? Log of oscillator strengthphys.atmol.oscStrengthfloatnullableEW1[1.6/260.2]? Equivalent width in HD2796 in mAngstrom units1e-13mspect.line.eqWidthfloatnullablef_EW1[syn ] syn=synthetic derived linewidth in EW1meta.codecharEW2[1.1/145.6]? Equivalent width in J1054+0528 in mAngstrom units1e-13mspect.line.eqWidthfloatnullablef_EW2[syn ] syn=synthetic derived linewidth in EW2meta.codecharEW3[1.7/147.8]? Equivalent width in J1529+0804 in mAngstrom units1e-13mspect.line.eqWidthfloatnullablef_EW3[syn ] syn=synthetic derived linewidth in EW3meta.codecharEW4[1.3/232.1]? Equivalent width in J1645+4357 in mAngstrom units1e-13mspect.line.eqWidthfloatnullablef_EW4[syn ] syn=synthetic derived linewidth in EW4meta.codecharEW5[6.4/267]? Equivalent width in J2114-0616 in mAngstrom units1e-13mspect.line.eqWidthfloatnullablef_EW5[syn ] syn=synthetic derived linewidth in EW5meta.codecharEW6[1.1/218.5]? Equivalent width in J2216+2232 in mAngstrom units1e-13mspect.line.eqWidthfloatnullablef_EW6[syn ] syn=synthetic derived linewidth in EW6meta.codechar