J/AJ/151/82ivo://CDS.VizieR/J/AJ/151/82doi:10.26093/cds/vizier.51510082CDSRoederer I.U.Mateo M.Bailey III J.I.Song Y.Bell E.F.Crane J.D.,Loebman S.Nidever D.L.Olszewski E.W.Shectman S.A.Thompson I.B.,Valluri M.Walker M.G.2018-05-16T07:03:57Z2018-03-27T13:59:03ZCDS support team

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

cds-question@unistra.frgalaxiesgiant-starsinfrared-photometryvisible-astronomybroad-band-photometryradial-velocityspectroscopyline-intensitieseffective-temperaturechemical-abundancesThe ultra-faint dwarf (UFD) galaxy Reticulum 2 (Ret 2) was recently discovered in images obtained by the Dark Energy Survey (Diehl et al. 2014SPIE.9149E..0VD). We have observed the four brightest red giants in Ret 2 at high spectral resolution using the Michigan/Magellan Fiber System. We present detailed abundances for as many as 20 elements per star, including 12 elements heavier than the Fe group. We confirm previous detection of high levels of r-process material in Ret 2 (mean [Eu/Fe]=+1.69+/-0.05) found in three of these stars (mean [Fe/H]=-2.88+/-0.10). The abundances closely match the r-process pattern found in the well-studied metal-poor halo star CS 22892-052. Such r-process-enhanced stars have not been found in any other UFD galaxy, though their existence has been predicted by at least one model. The fourth star in Ret 2 ([Fe/H]=-3.42+/-0.20) contains only trace amounts of Sr ([Sr/Fe]=-1.73+/-0.43) and no detectable heavier elements. One r-process enhanced star is also enhanced in C (natal [C/Fe]~+1.1). This is only the third such star known, which suggests that the nucleosynthesis sites leading to C and r-process enhancements are decoupled. The r-process-deficient star is enhanced in Mg ([Mg/Fe]=+0.81+/-0.14), and the other three stars show normal levels of {alpha}-enhancement (mean [Mg/Fe]=+0.34+/-0.03). The abundances of other {alpha} and Fe-group elements closely resemble those in UFD galaxies and metal-poor halo stars, suggesting that the nucleosynthesis that led to the large r-process enhancements either produced no light elements or produced light-element abundance signatures indistinguishable from normal supernovae.2016AJ....151...82Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/AJ/151/82CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/ApJ/645/613 : Abundances of HD 221170 (Ivans+, 2006)J/ApJS/162/227 : Transition probabilities for SmII (Lawler+, 2006)J/ApJS/167/292 : Laboratory transition probabilities for Gd IIJ/ApJ/667/1267 : CrI transition probabilities (Sobeck+, 2007)J/ApJS/182/51 : Transition probabilities of rare earth elementsJ/ApJS/182/80 : Rare earth abundances (Sneden+, 2009)J/ApJS/194/35 : Atomic transition probabilities of Mn (Den Hartog+, 2011)J/ApJ/750/76 : r-process peaks elements in HD 160617 (Roederer+, 2012)J/ApJ/767/134 : Abundances of red giant stars in UFD galaxiesJ/ApJS/208/27 : Sun and HD 84937 TiII log(gf) and abundances (Wood+, 2013)J/ApJS/211/20 : NiI transition probability measurements (Wood+, 2014)J/ApJS/215/20 : Vanadium log(gf) and transition probabilitiesJ/MNRAS/441/3127 : FeI oscillator strengths for Gaia-ESO (Ruffoni+, 2014)J/ApJ/808/95 : Spectroscopy of Reticulum II (Simon+, 2015)J/ApJ/808/108 : M2FS stellar spectroscopy of Reticulum 2 (Walker+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/AJ/151/82https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/AJ/151/82http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/AJ/151/82https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/AJ/151/82https://vizier.iucaa.in/viz-bin/votable?-source=J/AJ/151/82http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/AJ/151/82GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/AJ/151/82/table14 (Basic stellar data (table 1) and parameters (table 4))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/AJ/151/82/table14?https://vizier.iucaa.in/viz-bin/conesearch/J/AJ/151/82/table14?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/AJ/151/82/table14?GETtext/xml+votable180.050000true53.69974-54.090280.0055555555555555566/33626 33627https://cdsarc.cds.unistra.fr/viz-bin/moc/J/AJ/151/82?format=asciiInfraredOpticaldefaultJ/AJ/151/82/table14Basic stellar data (table 1) and parameters (table 4)e_[M/H][0.2] Uncertainty in [M/H]log(Sun)stat.error;phys.abundfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStar[1/4] Star name from this work (Star N)meta.id;meta.mainintDESDark Energy Survey (DES, Diehl et al. 2014SPIE.9149E..0VD) star name from Simon et al. (2015, J/ApJ/808/95) (DES JHHMMSS.ss+DDMMSS.s)meta.idcharRet2-[80/178]? Star name from Walker et al. (2015, J/ApJ/808/108) (Ret2-NNN)meta.idintnullablegmag[16.47/17.57] Star g-band magnitude, adopted from Koposov et al. (2015ApJ...805..130K)magphot.mag;em.opt.Bfloatg-r[0.56/0.80] Star g-r color, adopted from Koposov et al. (2015ApJ...805..130K)magphot.color;em.opt.B;em.opt.Rfloat<HRV>[59.7/65.5] Mean calculated heliocentric radial velocitykm/sspect.dopplerVeloc;stat.meanfloatS/N4300[15/26] Spectral signal-to-noise ratio at 4300{AA}stat.snrintS/N4800[26/45] Spectral signal-to-noise ratio at 4800{AA}stat.snrintS/N5200[33/59] Spectral signal-to-noise ratio at 5200{AA}stat.snrintTeff[4710/5020] Derived stellar effective temperatureKphys.temperature.effectiveinte_Teff[140] Uncertainty in TeffKstat.error;phys.temperature.effectiveintlogg[1.22/2.09] Derived log of surface gravitylog(cm.s**-2)phys.gravityfloate_logg[0.38/0.40] Uncertainty in logglog(cm.s**-2)stat.errorfloatVt[2.00/2.85] Derived microturbulence velocitykm/sphys.veloc.microTurbfloate_Vt[0.2/0.3] Uncertainty in Vtkm/sstat.errorfloat[M/H][-3.3/-2.7] Model derived metallicitylog(Sun)phys.abund.Z;meta.modelledfloatSimbadSimbad column added by the CDSmeta.ref.urlchar_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/AJ/151/82/table5Abundances Derived from Individual LinesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintStar[1/4] Star name from this work (Star N)meta.id;meta.mainintIonSpeciesphys.atmol.ionStagecharWave[4149.20/5429.70] Wavelength {lambda} ({AA})0.1nmem.wlfloatl_logeps[<] Limit flag on logepsmeta.code.errorcharlogeps[-2.59/5.35] Log {epsilon} abundancephys.abundfloate_logeps[0.15/0.57]? Error on logepsstat.errorfloatnullableJ/AJ/151/82/table3Equivalent Widths and Atomic DataIonSpeciesphys.atmol.ionStagecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintWave[4149.20/5429.70] Wavelength {lambda} ({AA})0.1nmem.wlfloatExPot[0.00/4.47] Excitation potentialeVphys.atmol.excitationfloatlog(gf)[-5.62/0.65] Log of degeneracy times oscillator strengthphys.atmol.oscStrengthfloatr_log(gf)[1/29] Literature reference for log(gf) value (1)meta.ref;pos.frameintf_EW-1[ls] Flag on EW-1 (2)meta.codecharEW-1[17.7/144.7]? Equivalent width for Star 1 (m{AA})0.1pmspect.line.eqWidthfloatnullablef_EW-2[ls] Flag on EW-2 (2)meta.codecharEW-2[21.3/238.1]? Equivalent width for Star 2 (m{AA})0.1pmspect.line.eqWidthfloatnullablef_EW-3[ls] Flag on EW-3 (2)meta.codecharEW-3[6.4/190.3]? Equivalent width for Star 3 (m{AA})0.1pmspect.line.eqWidthfloatnullablef_EW-4[ls] Flag on EW-4 (2)meta.codecharEW-4[8.4/220.3]? Equivalent width for Star 4 (m{AA})0.1pmspect.line.eqWidthfloatnullable