J/AJ/160/173ivo://CDS.VizieR/J/AJ/160/173doi:10.26093/cds/vizier.51600173CDSReggiani H.Schlaufman K.C.Casey A.R.Ji A.P.2021-09-28T05:53:07Z2020-12-01T12:58:27ZCDS support team

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

cds-question@unistra.frmilky-way-galaxychemically-peculiar-starsvisible-astronomychemical-abundancesThe bulge is the oldest component of the Milky Way. Since numerous simulations of Milky Way formation have predicted that the oldest stars at a given metallicity are found on tightly bound orbits, the Galaxy's oldest stars are likely metal-poor stars in the inner bulge with small apocenters (i.e., Rapo <~4kpc). In the past, stars with these properties have been impossible to find due to extreme reddening and extinction along the line of sight to the inner bulge. We have used the mid-infrared metal-poor star selection of Schlaufman & Casey (2014) on Spitzer/Galactic Legacy Infrared Mid-Plane Survey Extraordinaire data to overcome these problems and target candidate inner bulge metal-poor giants for moderate-resolution spectroscopy with Anglo-Australian Telescope/AAOmega. We used those data to select three confirmed metal-poor giants ([Fe/H]=-3.15, -2.56, -2.03) for follow-up high-resolution Magellan/Magellan Inamori Kyocera Echelle spectroscopy. A comprehensive orbit analysis using Gaia DR2 astrometry and our measured radial velocities confirms that these stars are tightly bound inner bulge stars. We determine the elemental abundances of each star and find high titanium and iron-peak abundances relative to iron in our most metal-poor star. We propose that the distinct abundance signature we detect is a product of nucleosynthesis in the Chandrasekhar-mass thermonuclear supernova of a CO white dwarf accreting from a helium star with a delay time of about 10Myr. Even though chemical evolution is expected to occur quickly in the bulge, the intense star formation in the core of the nascent Milky Way was apparently able to produce at least one Chandrasekhar-mass thermonuclear supernova progenitor before chemical evolution advanced beyond [Fe/H]~-3.2020AJ....160..173Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/160/173CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toB/simbad : Simbad objects catalogue (M.Wenger 2000)I/337 : Gaia DR1 (Gaia Collaboration, 2016)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/358 : SkyMapper Southern Sky Survey. DR1.1 (Wolf+, 2018)VII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/A+A/416/1117 : Abundances in the early Galaxy (Cayrel+, 2004)J/ApJ/608/405 : Explosive yields of massive star (Z=0-Zsun) (Chieffi+, 2004)J/A+A/501/519 : Extremely metal-poor turnoff stars abund. (Bonifacio+, 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/ApJ/743/156 : NEOWISE obs. of NEOs: preliminary results (Mainzer+, 2011)J/ApJ/749/175 : Abundances for stars in Plaut's window (Johnson+, 2012)J/ApJ/769/57 : Equivalent widths of metal-poor stars (Frebel+, 2013)J/AJ/145/107 : Zr, Ba, La, and Eu abund. in open clusters (Jacobson+, 2013)J/AJ/147/136 : Stars very low metal abundance VI. Abund. (Roederer+, 2014)J/ApJ/797/13 : Abundances of bright metal-poor stars (Schlaufman+, 2014)J/A+A/586/A49 : r- & s- process elements Milky Way disk (Battistini+, 2016)J/MNRAS/460/884 : EMBLA survey. Galactic bulge metal-poor stars (Howes+, 2016)J/A+A/605/A89 : Abund. of microlensed Bulge dwarf stars VI. (Bensby+, 2017)J/ApJ/850/179 : 2MASSJ15111324-2130030 metal-poor star abund (Casey+, 2017)J/A+A/608/A46 : Constraining cosmic scatter (Reggiani+, 2017)J/AJ/156/18 : APOGEE DR14:Binary companions stars (Price-Whelan+, 2018)J/A+A/631/A80 : Mn lines 3D NLTE formation late-type stars (Bergemann+,2019)J/MNRAS/488/2283 : COMBS survey. Galactic Bulge metal-poor stars (Lucey+, 2019)J/A+A/638/A76 : StarHorse data for 5 surveys (Queiroz+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/160/173https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/160/173http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/160/173https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/160/173https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/160/173http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/160/173GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/160/173/table1 (Log of Magellan/MIKE observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/160/173/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/160/173/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/160/173/table1?GETtext/xml+votable180.050000true261.2197931-28.24980190.0055555555555555566/28731 28734 28847https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/160/173?format=asciiOpticaldefaultJ/AJ/160/173/table1Log of Magellan/MIKE observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordint2MASSStellar identifiermeta.id;meta.maincharprimary2massDisplay data from 2MASS all-Sky catalog (II/246)meta.ref.urlintnullableObs[2017] UT year of observationtime.epoch;obsObs.SHour of observation starttime.epochnullableObs.EHour of observation endtime.epochnullableSlit[0.7/1] Slit widtharcsecspect.line.widthfloatTexp[660/4800] Exposure timestime.duration;obs.exposureintRVel[-196.42/9.23] Radial velocitykm/sphys.veloc;pos.heliocentricfloatNobsNumber of observations (link to table3)meta.numberintnullableEPInteractive Plotmeta.ref.urlcharSimbadNameSimbad column added by the CDSmeta.idchar_RAPosition from SIMBAD (right ascension part)degpos.eq.ra;meta.main_DEPosition from SIMBAD (declination part)degpos.eq.dec;meta.mainJ/AJ/160/173/table3Line list, equivalent-width measurements, and abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDStellar identifiermeta.id;meta.maincharWave[3813/7789] Wavelength; Angstroms0.1nmem.wldoubleIonIon identifierphys.atmol.ionStagecharEP[0/5.082] Excitation potentialeVphys.atmol.excitationfloatloggf[-4.76/0.54] log oscillator strengthphys.atmol.oscStrengthfloatEW[1.8/344] Equivalent width; milli-Angstroms1e-13mspect.line.eqWidthfloatAbund[-1.722/5.902] Abundance ({epsilon}_x_)phys.abundfloat