J/MNRAS/449/761ivo://CDS.VizieR/J/MNRAS/449/761doi:10.26093/cds/vizier.74490761CDSUral U.Cescutti G.Koch A.Kleyna J.Feltzing S.Wilkinson M.I.2024-08-14T20:21:31Z2018-01-29T14:29:24ZCDS support team

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

cds-question@unistra.frgalaxieschemically-peculiar-starsline-intensitiesWe present detailed chemical element abundance ratios of 17 elements with eight<=Z<=60 in three metal-poor stars in the Ursa Minor dwarf spheroidal galaxy, which we combine with extant data from the literature to assess the predictions of a novel suite of galaxy chemical evolution models. The spectroscopic data were obtained with the Keck/High-Resolution Echelle Spectrograph instrument and revealed low metallicities of [Fe/H]=-2.12, -2.13 and -2.67 dex. While the most metal-poor star in our sample shows an overabundance of [Mn/Fe] and other Fe-peak elements, our overall findings are in agreement with previous studies of this galaxy: elevated values of the [{alpha}/Fe] ratios that are similar to, or only slightly lower than, the halo values but with SN Ia enrichment at very low metallicity, as well as an enhancement of the ratio of first to second peak neutron capture elements [Y/Ba] with decreasing metallicity. The chemical evolution models which were tailored to reproduce the metallicity distribution function of the dwarf spheroidal, indicate that Ursa Minor had an extended star formation which lasted nearly 5 Gyr with low efficiency and are able to explain the [Y/Ba] enhancement at low metallicity for the first time. In particular, we show that the present-day lack of gas is probably due to continuous loss of gas from the system, which we model as winds.2015MNRAS.449..761Uhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/449/761CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/AJ/90/2221 : UMi dwarf galaxy BV photometry (Olszewski+, 1985)J/AJ/110/2131 : M/L for Draco and UMi. I. (Armandroff+ 1995)J/AJ/124/3222 : VI photometry of Draco and UMi galaxies (Bellazzini+, 2002)J/AJ/125/1352 : Ursa Minor dSph M,T2, DDO51 photometry (Palma+, 2003)J/ApJ/617/L41 : Red giant variable candidates in UMi dSph (Mighell+, 2004)J/ApJ/719/931 : Chemical evolution of the UMi dSph (Cohen+, 2010)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/449/761https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/449/761http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/449/761https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/449/761https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/449/761http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/449/761GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/449/761/table1 (Observed stars)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/449/761/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/449/761/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/449/761/table1?GETtext/xml+votable180.050000true226.466833366.69168060.0055555555555555566/11690 120322.367228618189496e-19 3.9105737390043815e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/449/761?format=asciidefaultJ/MNRAS/449/761/table1Observed starsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStarTarget star name (UMINNN)meta.id;meta.maincharImagJohnson-Cousins I-band magnitude from Kleyna et al. (1998AJ....115.2359K)magphot.mag;em.opt.IfloatVmagJohnson-Cousins V-band magnitude from Kleyna et al. (1998AJ....115.2359K)magphot.mag;em.opt.VfloatKmag2MASS K-band magnitudemagphot.mag;em.IR.KfloatRAJ2000Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of Declination (J2000)pos.eq.dec;meta.mainTeffphPhotometric effective temperature from (V-I) (1)Kphys.temperature.effectiveintTeffsSpectroscopic effective temperature (2)Kphys.temperature.effectiveintloggSurface gravity (1) (2)log(cm.s**-2)phys.gravityfloatVtMicroturbulence velocity (2)km/sphys.veloc.microTurbfloat[Fe/H]Metallicity (2)phys.abund.ZfloatRVRadial velocitykm/sphys.veloc;pos.heliocentricfloatEWEquivalent widths from table2meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlcharJ/MNRAS/449/761/table2Equivalent width measurementsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintElElementphys.atmol.elementcharlambdaWavelength of the absorption line {lambda} ({AA})0.1nmem.wl;spect.linefloatEPExcitation energy of the lower energy leveleVphys.energy;phys.atmol.levelfloatloggfOscilator strengthphys.atmol.collStrengthfloatEW-UMI396? Equivalent width of the line measured for the star UMI396 (m{AA})0.1pmspect.line.eqWidthfloatnullableEW-UMI718? Equivalent width of the line measured for the star UMI718 (m{AA})0.1pmspect.line.eqWidthfloatnullableEW-UMI446? Equivalent width of the line measured for the star UMI446 (m{AA})0.1pmspect.line.eqWidthfloatnullable