J/ApJ/763/61ivo://CDS.VizieR/J/ApJ/763/61doi:10.26093/cds/vizier.17630061CDSGilmore G.Norris J.E.Monaco L.Yong D.Wyse R.F.G.Geisler D.2017-06-01T08:49:37Z2014-10-31T11:16:31ZCDS support team

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

cds-question@unistra.frchemical-abundancesgiant-starsradial-velocityline-intensitiesWe present a double-blind analysis of high-dispersion spectra of seven red giant members of the Bootes I ultrafaint dwarf spheroidal galaxy, complemented with re-analysis of a similar spectrum of an eighth-member star. The stars cover [Fe/H] from -3.7 to -1.9 and include a CEMP-no star with [Fe/H]=-3.33. We conclude from our chemical abundance data that Bootes I has evolved as a self-enriching star-forming system, from essentially primordial initial abundances. This allows us uniquely to investigate the place of CEMP-no stars in a chemically evolving system, in addition to limiting the timescale of star formation. The elemental abundances are formally consistent with a halo-like distribution, with enhanced mean [{alpha}/Fe] and small scatter about the mean. This is in accord with the high-mass stellar initial mass function in this low-stellar-density, low-metallicity system being indistinguishable from the present-day solar neighborhood value. There is a non-significant hint of a decline in [{alpha}/Fe] with [Fe/H]; together with the low scatter, this requires low star formation rates, allowing time for supernova ejecta to be mixed over the large spatial scales of interest. One star has very high [Ti/Fe], but we do not confirm a previously published high value of [Mg/Fe] for another star. We discuss the existence of CEMP-no stars, and the absence of any stars with lower CEMP-no enhancements at higher [Fe/H], a situation that is consistent with knowledge of CEMP-no stars in the Galactic field. We show that this observation requires there be two enrichment paths at very low metallicities: CEMP-no and "carbon-normal."2013ApJ...763...61Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/763/61CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/294 : The SDSS Photometric Catalog, Release 7 (Adelman-McCarthy+, 2009)J/A+A/562/A146 : Chemical abundances of 8 metal-poor stars (Ishigaki+, 2014)J/ApJ/736/146 : Radial velocities of stars in Bootes I (Koposov+, 2011)J/ApJ/723/1632 : Abundance spreads in Bootes I and Segue 1 (Norris+, 2010)J/ApJ/711/350 : Metal-poor giant Boo-1137 abundances (Norris+, 2010)J/A+A/509/A93 : Carbon-enhanced metal-poor stars (Masseron+, 2010)J/MNRAS/380/281 : Faint galactic satellites spectrosc. survey (Martin+, 2007)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/763/61https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/763/61http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/763/61https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/763/61https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/763/61http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/763/61GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/763/61/stars (Bootes I red giant program stars with RVs, atmospheric parameters and adopted {alpha}-element abundances)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/763/61/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/763/61/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/763/61/stars?GETtext/xml+votable180.050000true210.04887514.41705560.0055555555555555566/8744 8745https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/763/61?format=asciiOpticaldefaultJ/ApJ/763/61/table4*NY atomic data, equivalent widths, and absolute abundancesIonSpecies identifierphys.atmol.ionStagecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlambda[4810/6644] Wavelength {lambda} ({AA})0.1nmem.wlfloatchiExcitation potentialeVphys.atmol.excitationfloatlog(gf)Log of the oscillator strengthphys.atmol.oscStrengthfloatEW33? Equivalent width in Boo 33 (m{AA})1e-13mspect.line.eqWidthfloatnullableloge33? Log absolute abundance in Boo 33 (2)phys.abundfloatnullableEW41? Equivalent width in Boo 41 (m{AA})1e-13mspect.line.eqWidthfloatnullableloge41? Log absolute abundance in Boo 41 (2)phys.abundfloatnullableEW94? Equivalent width in Boo 94 (m{AA})1e-13mspect.line.eqWidthfloatnullableloge94? Log absolute abundance in Boo 94 (2)phys.abundfloatnullableEW117? Equivalent width in Boo 117 (m{AA})1e-13mspect.line.eqWidthfloatnullableloge117? Log absolute abundance in Boo 117 (2)phys.abundfloatnullableEW119? Equivalent width in Boo 119 (m{AA})1e-13mspect.line.eqWidthfloatnullableloge119? Log absolute abundance in Boo 119 (2)phys.abundfloatnullableEW127? Equivalent width in Boo 127 (m{AA})1e-13mspect.line.eqWidthfloatnullableloge127? Log absolute abundance in Boo 127 (2)phys.abundfloatnullableEW130? Equivalent width in Boo 130 (m{AA})1e-13mspect.line.eqWidthfloatnullableloge130? Log absolute abundance in Boo 130 (2)phys.abundfloatnullableJ/ApJ/763/61/table5*GM atomic data, equivalent widths, and absolute abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIonSpecies identifierphys.atmol.ionStagecharlambda[4810/6768] Wavelength {lambda} ({AA})0.1nmem.wldoublechiExcitation potential {chi}eVphys.atmol.excitationfloatlog(gf)Log of the oscillator strengthphys.atmol.oscStrengthfloatEW33? Equivalent width in Boo 33 (1)1e-13mspect.line.eqWidthfloatnullableloge33? Log absolute abundance in Boo 33 (2)phys.abundfloatnullableEW41? Equivalent width in Boo 41 (1)1e-13mspect.line.eqWidthfloatnullableloge41? Log absolute abundance in Boo 41 (2)phys.abundfloatnullableEW94? Equivalent width in Boo 94 (1)1e-13mspect.line.eqWidthfloatnullableloge94? Log absolute abundance in Boo 94 (2)phys.abundfloatnullableEW117? Equivalent width in Boo 117 (1)1e-13mspect.line.eqWidthfloatnullableloge117? Log absolute abundance in Boo 117 (2)phys.abundfloatnullableEW119? Equivalent width in Boo 119 (1)1e-13mspect.line.eqWidthfloatnullableloge119? Log absolute abundance in Boo 119 (2)phys.abundfloatnullableEW127? Equivalent width in Boo 127 (1)1e-13mspect.line.eqWidthfloatnullableloge127? Log absolute abundance in Boo 127 (2)phys.abundfloatnullableEW130? Equivalent width in Boo 130 (1)1e-13mspect.line.eqWidthfloatnullableloge130? Log absolute abundance in Boo 130 (2)phys.abundfloatnullableJ/ApJ/763/61/starsBootes I red giant program stars with RVs, atmospheric parameters and adopted {alpha}-element abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStar[33/1137] Star numbermeta.id;meta.mainintf_Star[d] d: CEMP-no star (Carbon-Enhanced Metal-Poor with no enhancement of heavy neutron-capture elements over Solar ratios )meta.codechar[Mg/Fe][0.1/1.1] Magnesium abundancelog(Sun)phys.abundfloate_[Mg/Fe][0.1/0.3] [Mg/Fe] uncertainty (1)log(Sun)stat.error;phys.abundfloat[Ca/Fe][0.1/0.6] Calcium abundancelog(Sun)phys.abundfloate_[Ca/Fe][0.05/0.2] [Ca/Fe] uncertainty (1)log(Sun)stat.error;phys.abundfloat[Ti/Fe][-0.02/0.8] Titanium abundancelog(Sun)phys.abundfloate_[Ti/Fe][0.1/0.3] [Ti/Fe] uncertainty (1)log(Sun)stat.error;phys.abundfloat[a/Fe][0.1/0.8] {alpha}-elements abundance (2)log(Sun)phys.abundfloate_[a/Fe][0.09/0.2] [a/Fe] uncertainty (3)log(Sun)stat.error;phys.abundfloat[Fe/H][-3.7/-1.8] Iron abundancelog(Sun)phys.abund.Fefloate_[Fe/H][0.1/0.2] [Fe/H] uncertainty (1)log(Sun)stat.error;phys.abund.FefloatM07? Identification number from Martin+, 2007, Cat. J/MNRAS/380/281meta.idintnullableL11? Identification number from Lai+ (2011ApJ...738...51L)meta.idintnullableRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.maing0mag[17.4/18.4] SDSS-DR7 g_0_-band magnitude (1)magphot.mag;em.opt.Bfloatnullable(g-r)0[0.6/0.9] (g-r)_0_ color index (1)magphot.color;em.opt.B;em.opt.Rfloatnullable[Fe/H]a[-3/-1.4]? Abundance [Fe/H] using CaIIK line (2)log(Sun)phys.abund.Fe;spect.linefloatnullable[Fe/H]b[-3/-1.6]? Abundance [Fe/H] using CaII IR triplet (3)log(Sun)phys.abund.Fefloatnullable[Fe/H]c[-4/-1.6]? Abundance [Fe/H] (4)log(Sun)phys.abund.FefloatnullableRVnyRadial velocity determined by Norris & Yongkm/sphys.veloc;pos.heliocentricfloatnullablee_RVnyInternal standard error in RVnykm/sstat.errorfloatnullableo_RVnyNumber of individual spectra that were measuredmeta.numberintnullableRVgmRadial velocity determined by Geisler & Monacokm/sphys.veloc;pos.heliocentricfloatnullablee_RVgmInternal standard error in RVgmkm/sstat.errorfloatnullableo_RVgmNumber of individual spectra that were measuredmeta.numberintnullableHRV[92.5/107] Mean radial velocitykm/sspect.dopplerVeloc;stat.meanfloatnullableTeff1[4570/4790] Effective temperature (1)Kphys.temperature.effectiveintnullablelogg1[0.8/1.6] Surface gravity (1)log(cm.s**-2)phys.gravityfloatnullable[Fe/H]1[-3.3/-1.9] Abundance [Fe/H] (1)(4)log(Sun)phys.abund.FefloatnullableVt1[2.4/3.3] Microturbulent velocity (1)km/sphys.veloc.microTurbfloatnullableTeff2[4550/4800] Effective temperature (2)Kphys.temperature.effectiveintnullablelogg2[0.9/1.4] Surface gravity (2)log(cm.s**-2)phys.gravityfloatnullable[Fe/H]2[-3.44/-1.8] Abundance [Fe/H] (2)(4)log(Sun)phys.abund.FefloatnullableVt2[1.8/2.9] Microturbulent velocity (2)km/sphys.veloc.microTurbfloatnullablel_Teff3Limit flag on Teff3meta.code.errorcharnullableTeff3[4600/4600]? Effective temperature (3)Kphys.temperature.effectiveintnullablelogg3[0.5/1]? Surface gravity (3)log(cm.s**-2)phys.gravityfloatnullable[Fe/H]3[-2.95/-2.03]? Abundance [Fe/H] (3)(4)log(Sun)phys.abund.FefloatnullableVt3[2.1/2.1]? Microturbulent velocity (3)km/sphys.veloc.microTurbfloatnullableSloanDisplay the online SDSS data for the nearest objectmeta.ref.urlcharnullableSimbadSimbad column added by the CDSmeta.ref.urlcharnullable