J/ApJ/838/90ivo://CDS.VizieR/J/ApJ/838/90doi:10.26093/cds/vizier.18380090CDSO'Malley E.M.McWilliam A.Chaboyer B.Thompson I.2018-03-12T08:40:16Z2017-12-13T14:44:57ZCDS support team

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

cds-question@unistra.frchemically-peculiar-starschemical-abundancesline-intensitiesradial-velocityvisible-astronomytrigonometric-parallaxhst-photometryWe have performed a differential line-by-line chemical abundance analysis, ultimately relative to the Sun, of nine very metal-poor main-sequence (MS) halo stars, near [Fe/H]=-2dex. Our abundances range from -2.66<=[Fe/H]<=-1.40dex with conservative uncertainties of 0.07dex. We find an average [{alpha}/Fe]=0.34+/-0.09dex, typical of the Milky Way. While our spectroscopic atmosphere parameters provide good agreement with Hubble Space Telescope parallaxes, there is significant disagreement with temperature and gravity parameters indicated by observed colors and theoretical isochrones. Although a systematic underestimate of the stellar temperature by a few hundred degrees could explain this difference, it is not supported by current effective temperature studies and would create large uncertainties in the abundance determinations. Both 1D and <3D> hydrodynamical models combined with separate 1D non-LTE effects do not yet account for the atmospheres of real metal-poor MS stars, but a fully 3D non-LTE treatment may be able to explain the ionization imbalance found in this work.2017ApJ...838...90Ohttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/838/90CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)I/259 : The Tycho-2 Catalogue (Hog+ 2000)J/ApJ/469/355 : Teff, B-V and BC relation (Flower, 1996)J/A+A/326/751 : Chemical composition of halo and disk stars (Nissen+, 1997)J/A+A/356/238 : Atmospheric param. in metal-poor stars. III. (Carretta+ 2000)J/AJ/120/1841 : Abundances & Kinematics of Halo & Disk Stars (Fulbright 2000)J/AJ/124/1144 : Orbits of 171 single-lined spectroscopic bin. (Latham, 2002)J/A+A/404/187 : Equivalent widths for metal-poor stars (Gratton+, 2003)J/A+A/433/185 : Detailed abundance analysis of F and G dwarfs (Bensby+, 2005)J/A+A/442/961 : Lithium content of the Galactic Halo stars (Charbonnel+, 2005)J/ApJS/159/141 : Spectroscopic properties of cool stars. I. (Valenti+, 2005)J/AJ/131/2949 : Mn abundances in cluster and field stars (Sobeck+, 2006)J/AJ/135/1551 : Abundances of stars in 47 Tuc (Koch+, 2008)J/A+A/512/A54 : Teff and Fbol from Infrared Flux Method (Casagrande+, 2010)J/A+A/511/L10 : Abundances and space velocities of 94 stars (Nissen+, 2010)J/ApJ/743/140 : Abundances (Be,{alpha}) in metal-poor stars (Boesgaard+, 2011)J/A+A/530/A138 : Geneva-Copenhagen survey re-analysis (Casagrande+, 2011)J/AJ/142/63 : Abundance of five stars in NGC 6397 (Koch+, 2011)J/ApJ/735/41 : Carbon and oxygen abundances in FGK stars (Petigura+, 2011)J/A+A/526/A99 : Metal-poor solar-type stars spectro. and masses (Sousa+, 2011)J/ApJ/753/64 : Detailed abundances for 97 metal-poor stars (Ishigaki+, 2012)J/A+A/557/A26 : STAGGER-grid of 3D stellar models. I. (Magic+, 2013)J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)J/MNRAS/454/2863 : Teff against colours calibrations (Huang+, 2015)J/ApJ/835/152 : HST FGS-1r parallaxes for 8 metal-poor stars (Chaboyer+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/838/90https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/838/90http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/838/90https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/838/90https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/838/90http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/838/90GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/838/90/targets (Target star observations and stellar abundances (tables 1 and 11))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/838/90/targets?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/838/90/targets?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/838/90/targets?GETtext/xml+votable180.050000true141.0873911-80.52258250.0055555555555555566/9992 13829 14679 15658 25820 27128 29451 29596 30553 369192.76124552865182e-19 3.9057996558789745e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/838/90?format=asciiOpticaldefaultJ/ApJ/838/90/table4Solar and HIP 66815 line equivalent widthsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpecies to be measuredphys.atmol.ionStagecharlambda[4730/8773] Wavelength of spectral line; in Angstrom units0.1nmem.wl;spect.linedoubleEP[0/68] Excitation PotentialeVphys.atmol.excitationfloatHIP66815[3/126] Equivalent width for HIP 66815 (1)1e-13mspect.line.eqWidthfloatSun[8/113]? Equivalent width for Sun (1)1e-13mspect.line.eqWidthfloatnullableJ/ApJ/838/90/table2Fe line listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpecies being measuredphys.atmol.ionStagecharlambda[4447.7/6750.2] Wavelength of spectral line; in Angstrom units0.1nmem.wl;spect.linefloatEP[0.09/5] Excitation Potential of spectral lineeVphys.atmol.excitation;spect.linefloatHIP46120? Equivalent width for HIP 46120 (1)1e-13mspect.line.eqWidthfloatnullableHIP54639? Equivalent width for HIP 54639 (1)1e-13mspect.line.eqWidthfloatnullableHIP80679? Equivalent width for HIP 80679 (1)1e-13mspect.line.eqWidthfloatnullableHIP87062? Equivalent width for HIP 87062 (1)1e-13mspect.line.eqWidthfloatnullableHIP87788? Equivalent width for HIP 87788 (1)1e-13mspect.line.eqWidthfloatnullableHIP98492? Equivalent width for HIP 98492 (1)1e-13mspect.line.eqWidthfloatnullableHIP103269? Equivalent width for HIP 103269 (1)1e-13mspect.line.eqWidthfloatnullableHIP106924? Equivalent width for HIP 106924 (1)1e-13mspect.line.eqWidthfloatnullableHIP108200? Equivalent width for HIP 108200 (1)1e-13mspect.line.eqWidthfloatnullableJ/ApJ/838/90/table3Alpha-element line listrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpecies being measuredphys.atmol.ionStagecharlambda[4283/8718] Wavelength of spectral line0.1nmem.wl;spect.linefloatEP[0/9.2] Excitation Potential of spectral lineeVphys.atmol.excitation;spect.linefloatHIP46120[1/142]? Equivalent width for HIP 46120 (1)1e-13mspect.line.eqWidthfloatnullableHIP54639[0.6/217]? Equivalent width for HIP 54639 (1)1e-13mspect.line.eqWidthfloatnullableHIP80679[0.2/186]? Equivalent width for HIP 80679 (1)1e-13mspect.line.eqWidthfloatnullableHIP87062[0.3/144]? Equivalent width for HIP 87062 (1)1e-13mspect.line.eqWidthfloatnullableHIP87788[0.2/151]? Equivalent width for HIP 87788 (1)1e-13mspect.line.eqWidthfloatnullableHIP98492[1/221]? Equivalent width for HIP 98492 (1)1e-13mspect.line.eqWidthfloatnullableHIP103269[3/212]? Equivalent width for HIP 103269 (1)1e-13mspect.line.eqWidthfloatnullableHIP106924[0.4/107]? Equivalent width for HIP 106924 (1)1e-13mspect.line.eqWidthfloatnullableHIP108200[1/280]? Equivalent width for HIP 108200 (1)1e-13mspect.line.eqWidthfloatnullableJ/ApJ/838/90/targetsTarget star observations and stellar abundances (tables 1 and 11)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHIP[46120/108200] HIP numbermeta.id;meta.mainintf_HIPs= our standard star HIP 66815meta.codecharTelTelescopemeta.id;instr.telcharDateUT date of observationtime.epoch;obsnullableS/N[76.5/254] Signal to noise ratio (1)pixel**-1stat.snrfloatF606W[9.9/11.4]? HST F606W magnitudemagphot.mag;em.opt.RfloatnullablePlx[3.4/15.1]? HST parallax {pi}maspos.parallaxfloatnullableHRV[-309/85] Heliocentric radial velocitykm/sspect.dopplerVeloc;pos.heliocentricfloatpPDisplay data from previous paper (Chaboyer+, 2017, J/ApJ/835/152)meta.ref.urlchar[FeI/H][-2.7/-1.4] [FeI/H] abundancephys.abundfloatnullablee_[FeI/H][0.07] [FeI/H] uncertaintystat.error;phys.abundfloatnullable[FeII/H][-2.6/-1.3] [FeII/H] abundancephys.abundfloatnullablee_[FeII/H][0.1/0.3] [FeII/H] uncertaintystat.error;phys.abundfloatnullable[O/Fe][0.1/0.8]? [O/Fe] abundancephys.abundfloatnullablee_[O/Fe][0.05/0.08]? [O/Fe] uncertaintystat.error;phys.abundfloatnullable[Mg/Fe][0.05/0.5]? [Mg/Fe] abundancephys.abundfloatnullablee_[Mg/Fe][0.1/0.3]? [Mg/Fe] uncertaintystat.error;phys.abundfloatnullable[Ca/Fe][0.1/0.8] [Ca/Fe] abundancephys.abundfloatnullablee_[Ca/Fe][0.03/0.08] [Ca/Fe] uncertaintystat.error;phys.abundfloatnullableEWDisplay the Equivalent Widths for the corresponding star (tables 2-4)meta.ref.urlcharSimbadSimbad column added by the CDSmeta.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.main