J/ApJ/852/99ivo://CDS.VizieR/J/ApJ/852/99doi:10.26093/cds/vizier.18520099CDSNagasawa D.Q.Marshall J.L.Li T.S.Hansen T.T.Simon J.D.,Bernstein R.A.Balbinot E.Drlica-Wagner A.Pace A.B.Strigari L.E.,Pellegrino C.M.DePoy D.L.Suntzeff N.B.Bechtol K.Walker A.R.,Abbott T.M.C.Abdalla F.B.Allam S.Annis J.Benoit-Levy A.Bertin E.,Brooks D.Carnero Rosell A.Carrasco Kind M.Carretero J.Cunha C.E.,D'Andrea C.B.da Costa L.N.Davis C.Desai S.Doel P.Eifler T.F.,Flaugher B.Fosalba P.Frieman J.Garcia-Bellido J.Gaztanaga E.,Gerdes D.W.Gruen D.Gruendl R.A.Gschwend J.Gutierrez G.,Hartley W.G.Honscheid K.James D.J.Jeltema T.Krause E.Kuehn K.,Kuhlmann S.Kuropatkin N.March M.Miquel R.Nord B.Roodman A.,Sanchez E.Santiago B.Scarpine V.Schindler R.Schubnell M.,Sevilla-Noarbe I.Smith M.Smith R.C.Soares-Santos M.Sobreira F.,Suchyta E.Tarle G.Thomas D.Tucker D.L.Wechsler R.H.Wolf R.C.,Yanny B.2019-01-28T04:54:41Z2018-11-05T14:08:48ZCDS support team

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

cds-question@unistra.frchemical-abundancesgalaxiesspectroscopychemically-peculiar-starsWe present chemical abundance measurements of three stars in the ultrafaint dwarf galaxy Horologium I, a Milky Way satellite discovered by the Dark Energy Survey. Using high-resolution spectroscopic observations, we measure the metallicity of the three stars, as well as abundance ratios of several {alpha}-elements, iron-peak elements, and neutron-capture elements. The abundance pattern is relatively consistent among all three stars, which have a low average metallicity of [Fe/H]~-2.6 and are not {alpha}-enhanced ([{alpha}/Fe]~0.0). This result is unexpected when compared to other low-metallicity stars in the Galactic halo and other ultrafaint dwarfs and suggests the possibility of a different mechanism for the enrichment of Hor I compared to other satellites. We discuss possible scenarios that could lead to this observed nucleosynthetic signature, including extended star formation, enrichment by a Population III supernova, and or an association with the Large Magellanic Cloud.2018ApJ...852...99Nhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/852/99CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/128/1177 : Galactic stellar abundances (Venn+, 2004)J/ApJS/167/292 : Transition probabilities for Gd II (Den Hartog+, 2006)J/ApJS/162/227 : Transition probabilities for SmII (Lawler+, 2006)J/ApJ/667/1267 : CrI transition probabilities (Sobeck+, 2007)J/AJ/135/1580 : Element abundances in ten red giants of Car dSph (Koch+, 2008)J/AJ/135/209 : Rotational and RVs 761 HIP giants (Massarotti+, 2008)J/A+A/480/379 : Abundances of 59 red giants in LMC (Pompeia+, 2008)J/ApJ/705/328 : Abundance measurements in Sculptor dSph (Kirby+, 2009)J/ApJS/182/51 : Transition prob. of rare earth elements (Lawler+, 2009)J/ApJS/182/80 : Rare earth abundances (Sneden+, 2009)J/AN/331/474 : Abundances of metal-poor stars (Frebel, 2010)J/ApJ/708/560 : Spectroscopy of UMa II and Coma Ber (Frebel+, 2010)J/ApJ/724/341 : Nucleosynthesis of massive metal-free stars (Heger+, 2010)J/ApJ/723/1632 : Abundance spreads in Bootes I and Segue 1 (Norris+, 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/144/88 : Spectrosc. of 6 LMC RR Lyrae & 3 SMC RR Lyrae (Haschke+, 2012)J/ApJ/761/33 : Chemical data of 89 stars in the LMC disk (Lapenna+, 2012)J/AJ/144/4 : Dwarf galaxies in the Local Group (McConnachie+, 2012)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/ApJ/763/61 : Abundances of 7 red giant members of BootesI (Gilmore+, 2013)J/A+A/560/A44 : Abundances of LMC bar and disk stars (Van der Swaelmen+, 2013)J/ApJ/767/134 : Abundances of red giant stars in UFD galaxies (Vargas+, 2013)J/ApJ/762/26 : Most metal-poor stars. II. Galactic halo stars (Yong+, 2013)J/ApJ/786/74 : EW measurements of 6 Segue 1 red giants (Frebel+, 2014)J/A+A/562/A146 : Chemical abundances of 8 metal-poor stars (Ishigaki+, 2014)J/ApJS/215/20 : Vanadium log(gf) and transition probabilities (Lawler+, 2014)J/A+A/571/A47 : Extensive linelist of CH in stellar atm. (Masseron+, 2014)J/MNRAS/440/2665 : SDSS J021933.13+200830.2 spectroscopy (Roederer+, 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/ApJS/214/26 : Line lists for CN isotopes transitions (Sneden+, 2014)J/ApJS/211/20 : NiI transition probability measurements (Wood+, 2014)J/ApJ/803/63 : gr photometry of stars in Kim 2 (Kim+, 2015)J/ApJS/220/13 : Co I transition probabilities (Lawler+, 2015)J/ApJ/808/95 : Spectroscopy of Reticulum II (Simon+, 2015)J/ApJ/802/93 : Abundance analysis of 5 stars in Sculptor (Simon+, 2015)J/ApJ/826/110 : Boo-127 and Boo-980 high-resolution spectra (Frebel+, 2016)J/ApJ/830/93 : Abundances of Ret II brightest red giant members (Ji+, 2016)J/ApJ/817/41 : Abundances of 4 metal-poor red giants in BooII (Ji+, 2016)J/AJ/151/82 : 4 brightest red giants in Ret 2 (Roederer+, 2016)J/ApJ/817/53 : Fe-group elemental abundances in HD84937 (Sneden+, 2016)J/ApJ/819/53 : Magellan/M2FS spectrosc. of Tucana 2 & Grus 1 (Walker+, 2016)J/ApJ/838/44 : Abundances of the brightest member of Tuc III (Hansen+, 2017)J/ApJ/838/83 : RVs, abundances & membership in TriII (Kirby+, 2017)J/ApJ/838/11 : Member stars in the MW satellite Tucana III (Simon+, 2017)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/852/99https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/852/99http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/852/99https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/852/99https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/852/99http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/852/99GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/852/99/stars (Dark Energy Survey (DES) astrometry and photometry, observing details and measured stellar parameters of 3 member stars of Hor I (tables 1, 2 and 4))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/852/99/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/852/99/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/852/99/stars?GETtext/xml+votable180.050000true43.91793-54.135340.0055555555555555566/33685https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/852/99?format=asciidefaultJ/ApJ/852/99/starsDark Energy Survey (DES) astrometry and photometry, observing details and measured stellar parameters of 3 member stars of Hor I (tables 1, 2 and 4)SimbadNameSimbad column added by the CDSmeta.idcharInstInstrumentmeta.id;instrcharf_gmagFlag on gmag (1)meta.codecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDESDES identifier (JHHMMSS+DDMMSS)meta.id;meta.maincharf_DESFlag on DES (1)meta.codecharRAJ2000[43.8/44] Right ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000[-54.2/-54] Declination in decimal degrees (J2000)degpos.eq.dec;meta.maingmag[17.7/18.7] DES g-band magnitudemagphot.mag;em.opt.Bfloatrmag[16.7/18] DES r-band magnitudemagphot.mag;em.opt.Rfloatimag[16.3/17.7] DES i-band magnitudemagphot.mag;em.opt.Ifloatzmag[16.1/17.6] DES z-band magnitudemagphot.mag;em.opt.IfloatYmag[16.1/17.5] DES Y-band magnitudemagphot.mag;em.IR.JfloatS/N5300[20/35] Signal to noise ration at 5300_{AA}stat.snrintS/N6300[20/40] Signal to noise ration at 6300_{AA}stat.snrintHRV[114.3/118.6] Heliocentric velocitykm/sspect.dopplerVeloc;pos.heliocentricfloate_HRV[0.5/0.6] HRV uncertaintykm/sstat.errorfloatTeff[4500/5000] Effective temperatureKphys.temperature.effectiveinte_Teff[100] Teff uncertaintyKstat.error;phys.temperature.effectiveintlogg[1.4/2] Log of surface gravitylog(cm.s**-2)phys.gravityfloate_logg[0.2] logg uncertaintylog(cm.s**-2)stat.errorfloatVt[0.8/3.5] Microturbulent velocitykm/sphys.velocfloate_Vt[0.5] Vt uncertaintykm/sstat.errorfloat[Fe/H][-2.9/-2.4] Metallicitylog(Sun)phys.abund.Zfloate_[Fe/H][0.1/0.2] Metallicity uncertaintylog(Sun)stat.error;phys.abund.Fefloat[Ca/Fe][-0.07/0] Abundance of [Ca/Fe]log(Sun)phys.abundfloate_[Ca/Fe][0.1/0.3] Abundance of [Ca/Fe] uncertaintylog(Sun)stat.error;phys.abundfloatJ/ApJ/852/99/table3Atomic line dataIonSpecies (1)phys.atmol.ionStagecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[3818.7/8688.7] Wavelength in Angstroms0.1nmem.wlfloatExPot[0/5.7]? Excitation potential (1)eVphys.atmol.excitationfloatnullablelog(gf)[-10.6/0.7]? Log of degeneracy times oscillator strength (1)phys.atmol.oscStrengthfloatnullableRef[1/30] Literature reference (2)meta.ref;pos.frameint