J/ApJ/865/129ivo://CDS.VizieR/J/ApJ/865/129doi:10.26093/cds/vizier.18650129CDSRoederer I.U.Sakari C.M.Placco V.M.Beers T.C.Ezzeddine R.,Frebel A.Hansen T.T.2019-10-02T12:34:27Z2019-10-02T13:30:46ZCDS support team

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

cds-question@unistra.frchemical-abundanceschemically-peculiar-starsline-intensitieshorizontal-branch-starsvisible-astronomyWe present a detailed abundance analysis of the bright (V=9.02), metal-poor ([Fe/H]=-1.47+/-0.08) field red horizontal-branch star HD222925, which was observed as part of an ongoing survey by the R-Process Alliance. We calculate stellar parameters and derive abundances for 46 elements based on 901 lines examined in a high-resolution optical spectrum obtained using the Magellan Inamori Kyocera Echelle spectrograph. We detect 28 elements with 38<=Z<=90; their abundance pattern is a close match to the solar r-process component. The distinguishing characteristic of HD222925 is an extreme enhancement of r-process elements ([Eu/Fe]=+1.33+/-0.08, [Ba/Eu]=-0.78+/-0.10) in a moderately metal-poor star, so the abundance of r-process elements is the highest ([Eu/H]=-0.14+/-0.09) in any known r-process-enhanced star. The abundance ratios among lighter (Z<=30) elements are typical for metal-poor stars, indicating that production of these elements was dominated by normal Type II supernovae, with no discernible contributions from Type Ia supernovae or asymptotic giant branch stars. The chemical and kinematic properties of HD 222925 suggest it formed in a low-mass dwarf galaxy, which was enriched by a high-yield r-process event before being disrupted by interaction with the Milky Way.2018ApJ...865..129Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/865/129CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)III/279 : RAVE 5th data release (Kunder+, 2017)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/AJ/103/1987 : Stars of very low metal abundance (Beers+ 1992)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/A+A/435/373 : Broadening of Fe II lines by H collisions (Barklem+, 2005)J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)J/ApJS/167/292 : Laboratory transitions for Gd II (Den Hartog+, 2006)J/ApJ/645/613 : Abundances of HD 221170 (Ivans+, 2006)J/ApJS/162/227 : Transition probabilities for SmII (Lawler+, 2006)J/AJ/132/85 : Equivalent width of 33 metal-poor RHB (Preston+, 2006)J/ApJ/655/492 : Equivalent widths of 26 metal-poor stars (Aoki+, 2007)J/ApJS/169/120 : Transition probabilities for HfII and Hf (Lawler+, 2007)J/A+A/465/271 : Oxygen abundances in nearby stars (Ramirez+, 2007)J/ApJ/667/1267 : CrI transition probabilities (Sobeck+, 2007)J/ApJ/701/1053 : Abundances of 8 stars in the Draco dSph (Cohen+, 2009)J/ApJS/182/51 : Transitions of rare earth elements (Lawler+, 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/719/931 : Chemical evolution of the UMi dSph (Cohen+, 2010)J/AJ/140/1694 : Abundances of non-variable red & blue HB stars (For+, 2010)J/ApJ/724/975 : Heavy elements abund. of metal-poor stars (Roederer+, 2010)J/ApJS/194/35 : Atomic transition probabilities of Mn (Den Hartog+, 2011)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)J/MNRAS/427/343 : Infrared excesses of Hipparcos stars (McDonald+, 2012)J/ApJ/750/76 : R-process peaks elements in HD 160617 (Roederer+, 2012)J/ApJ/775/L27 : Abundances in a metal-poor RGB star (Johnson+, 2013)J/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)J/ApJ/794/58 : Metal-poor stars in the Galaxy thick disk (Beers+, 2014)J/A+A/562/A71 : Abundances of solar neighbourhood dwarfs (Bensby+, 2014)J/ApJS/215/23 : FeI radiative lifetimes (Den Hartog+, 2014)J/ApJ/786/74 : EW measurements of 6 Segue 1 red giants (Frebel+, 2014)J/ApJS/215/20 : Vanadium log(gf) & transition probabilities (Lawler+, 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/MNRAS/441/3127 : FeI oscillator strengths for Gaia-ESO (Ruffoni+, 2014)J/ApJ/797/13 : Abundances of bright metal-poor stars (Schlaufman+, 2014)J/ApJS/214/18 : VII log(gf) values, and V abundance in HD 84937 (Wood+ 2014)J/ApJS/211/20 : NiI transition probability measurements (Wood+, 2014)J/A+A/577/A9 : Sc, V, Mn, and Co in Milky Way stars (Battistini+, 2015)J/A+A/581/A138 : Photom. variability in magnetic CP stars (Bernhard+, 2015)J/ApJ/807/171 : SkyMapper metal-poor star spectroscopy (Jacobson+, 2015)J/ApJS/220/13 : Co I transition probabilities (Lawler+, 2015)J/ApJ/808/103 : Kapteyn moving group star abundances (Navarrete+, 2015)J/A+A/586/A49 : r- & s- process elements in the MW disk (Battistini+, 2016)J/ApJ/830/93 : Abundances of Ret II brightest red giant members (Ji+, 2016)J/ApJ/817/53 : Fe-group abundance analysis in HD84937 (Sneden+, 2016)J/ApJ/819/53 : Magellan/M2FS spectroscopy of Tuc 2 & Grus 1 (Walker+, 2016)J/ApJ/847/142 : Ultra-metal-poor stars LTE & NLTE abund. (Ezzeddine+, 2017)J/ApJ/838/44 : Abundances of TucIII brightest members (Hansen+, 2017)J/A+A/607/A91 : CS 29497-004 abundances (Hill+, 2017)J/ApJS/228/10 : Transitions for 183 lines of Cr II (Lawler+, 2017)J/ApJ/844/18 : RAVE J203843.2-002333 high-res. spectroscopy (Placco+, 2017)J/AJ/155/240 : A spectroscopic survey of field RHB stars (Afsar+, 2018)J/ApJ/862/174 : Spectroscopy obs. of RAVE J094921.8-161722 (Gull+, 2018)J/ApJ/858/92 : RPA Southern Pilot Search of 107 Stars (Hansen+, 2018)J/ApJ/857/2 : Abundances in 6 metal-poor stars (Roederer+, 2018)J/ApJ/860/125 : Six warm metal-poor stars iron abundances (Roederer+, 2018)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/865/129https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/865/129http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/865/129https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/865/129https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/865/129http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/865/129GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/ApJ/865/129/refsReferencesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReference codemeta.noteintBibCodeBibcode of the referencemeta.bib.bibcodecharAuthAuthor's name(s)meta.bib.authorcharCommCommentmeta.notecharJ/ApJ/865/129/table2Lines, atomic data, EWs, and abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpeciesphys.atmol.ionStagecharlambda[3351.2/8220.4] Wavelength in Angstroms0.1nmem.wlfloatExPot[0/6.3] Excitation potentialeVphys.atmol.excitationfloatlog(gf)[-5.7/0.9] log of degeneracy times oscillator strengthphys.atmol.oscStrengthfloatr_log(gf)[1/49] Reference for log of degeneracy times oscillator strength (see refs.dat file)meta.ref;pos.frameintEW[0.9/139]? Equivalent width in milli Angstroms0.1pmspect.line.eqWidthfloatnullablel_log(eps)Limit on log epsilon abundancemeta.code.errorcharlog(eps)[-0.5/6.814] log epsilon abundancephys.abundfloat