J/ApJ/921/67ivo://CDS.VizieR/J/ApJ/921/67doi:10.26093/cds/vizier.19210067CDSCasey A.R.Ji A.P.Hansen T.T.Li T.S.Koposov S.E.Da Costa G.S.,Bland-Hawthorn J.Cullinane L.Erkal D.Lewis G.F.Kuehn K.,Mackey D.Martell S.L.Pace A.B.Simpson J.D.Zucker D.B.2023-05-16T14:25:08Z2023-03-28T16:05:52ZCDS support team

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

cds-question@unistra.frvisible-astronomyspectroscopygiant-starschemical-abundancesThe Phoenix stellar stream has a low intrinsic dispersion in velocity and metallicity that implies the progenitor was probably a low-mass globular cluster. In this work we use Magellan/Magellan Inamori Kyocera Echelle (MIKE) high-dispersion spectroscopy of eight Phoenix stream red giants to confirm this scenario. In particular, we find negligible intrinsic scatter in metallicity ({sigma}([FeII/H])=0.04_-0.03_^+0.11^) and a large peak-to-peak range in [Na/Fe] and [Al/Fe] abundance ratios, consistent with the light element abundance patterns seen in the most metal-poor globular clusters. However, unlike any other globular cluster, we also find an intrinsic spread in [SrII/Fe] spanning ~1dex, while [BaII/Fe] shows nearly no intrinsic spread ({sigma}([BaII/H])=0.03_-0.02_^+0.10^). This abundance signature is best interpreted as slow-neutron-capture element production from a massive fast-rotating metal-poor star (15-20M_{sun}_, v_ini_/v_crit_=0.4, [Fe/H]=-3.8). The low inferred cluster mass suggests the system would have been unable to retain supernovae ejecta, implying that any massive fast-rotating metal-poor star that enriched the interstellar medium must have formed and evolved before the globular cluster formed. Neutron-capture element production from asymptotic giant branch stars or magneto-rotational instabilities in core-collapse supernovae provide poor fits to the observations. We also report one Phoenix stream star to be a lithium-rich giant (A(Li)=3.1+/-0.1). At [Fe/H]=-2.93; it is among the most metal-poor lithium-rich giants known.2021ApJ...921...67Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/921/67CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toII/357 : The Dark Energy Survey (DES): Data Release 1 (Abbott+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)II/371 : The Dark Energy Survey (DES): Data Release 2 (Abbott+, 2021)J/AJ/120/1841 : Abund. & Kinematics of Halo and Disk Stars (Fulbright 2000)J/A+A/439/129 : HERES II. Spectroscopic analysis (Barklem+, 2005)J/A+A/505/117 : Abund. of red giants in 15 GCs (Carretta+, 2009)J/ApJ/708/560 : Spectroscopy of UMa II and Coma Ber (Frebel+, 2010)J/ApJ/731/64 : Spectroscopy of 300 RGBs in {omega} Cen (Marino+, 2011)J/AJ/141/175 : Abundances in M15 RGB/RHB stars (Sobeck+, 2011)J/MNRAS/434/1681 : Extremely metal-poor stars CaII triplet (Carrera+, 2013)J/ApJ/778/56 : Hamburg/ESO Survey extremely metal-poor stars (Cohen+, 2013)J/MNRAS/444/392 : Synthetic Stellar Photometry. I. (Casagrande+, 2014)J/ApJ/797/44 : Evolution and nucleosynthesis of AGB stars (Fishlock+, 2014)J/AJ/147/136 : Stars of very low metal abundance. VI. (Roederer+, 2014)J/ApJ/807/171 : SkyMapper Survey metal-poor star sp. (Jacobson+, 2015)J/ApJ/837/176 : Sp. obs. of 2 red giant stars in omega Cen (Yong+, 2017)J/ApJS/237/13 : Yields of 13-120M_{sun}_ massive stars (Limongi+, 2018)J/ApJ/870/83 : Abundances in GruI & TriII (Ji+, 2019)J/MNRAS/490/3508 : The Southern Stellar Stream Sp. Survey (S^5^) (Li+, 2019)J/AJ/158/14 : Stellar pop. of GCs using APOGEE (Nataf+, 2019)J/ApJ/885/3 : Membership in 12 stellar streams from DES (Shipp+, 2019)J/AJ/160/181 : Chemical abundances in red giants with Magellan (Ji+, 2020)J/other/Nat/583.768 : 2050 red giants CaII EWs (Wan+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/921/67https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/921/67http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/921/67https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/921/67https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/921/67http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/921/67GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/921/67/stars (Sky positions and exposure times for all stars observed (Table 1) and stellar parameters (Table 2))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/921/67/stars?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/921/67/stars?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/921/67/stars?GETtext/xml+votable180.050000true20.9515-53.95761110.0055555555555555566/34919 34943 35200 35202 35212 35215https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/921/67?format=asciiOpticaldefaultJ/ApJ/921/67/starsSky positions and exposure times for all stars observed (Table 1) and stellar parameters (Table 2)[M/H][-2.93/-2.52] Mean stellar metallicity (1)Sunphys.abund.Z;stat.meanfloatNabNumber of abundance measurements for this star (link to Table 3)meta.numberintnullableJ20Display data from Ji+ 2020, J/AJ/160/181meta.ref.urlcharDESDisplay the DES DR2 data (II/371) within 0.5"meta.ref.urlcharSlit[0.7/1] Slitarcsecinstr.setupfloatlogg[1.64/2.56] Log of surface gravitylog(cm.s**-2)phys.gravityfloate_logg[0.16/0.17] logg uncertaintylog(cm.s**-2)stat.errorfloatVt[1.47/2.11] Microturbulent velocitykm/sphys.velocfloatSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name (G1)meta.id;meta.maincharprimaryRAJ2000Hour of right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Degree of declination (J2000)pos.eq.dec;meta.mainGaiaGaia DR2 identifiermeta.idDateDate of observation (UT)time.epochnullableExp[30/134] Exposure timemintime.duration;obs.exposureintgmag[15.96/17.71] g-band magnitudemagphot.mag;em.opt.BfloatSN450[12/25] Signal-to-noise ratio at 450nmpixel**-1stat.snrintSN650[20/44] Signal-to-noise ratio at 650nmpixel**-1stat.snrintTeff[4905/5292] Effective temperatureKphys.temperature.effectiveinte_Teff[43/71] Teff uncertaintyKstat.error;phys.temperature.effectiveinte_Vt[0.07/0.6] Vt uncertaintykm/sstat.errorfloatJ/ApJ/921/67/table3Summary of stellar abundances, including differences due to a 1{sigma} change in stellar parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameStar name (G1)meta.id;meta.maincharIonElement and ionisation statephys.atmol.ionStagecharN[1/100] Number of transitions measuredmeta.numberintulIndicator that the measurement is an upper limitmeta.codecharloge[-1.8/9.02] The log(epsilon) abundancephys.abundfloat[X/H][-3.82/1.01] The [X/H] abundance ratiophys.abund;arith.ratiofloate_[X/H][0.04/0.6]? The 1-sigma uncertainty in [X/H] abundance ratiostat.error;phys.abundfloatnullable[X/Fe][-1.2/3.7] The [X/Fe] abundance ratiophys.abundfloate_[X/Fe][0/0.6]? The 1-sigma uncertainty in [X/Fe] abundance ratiostat.error;phys.abundfloatnullablelogeDelT[-0.03/0.14]? The abundance change due to a 1-sigma shift in effective temperature, {Delta}_T_phys.abund;arith.difffloatnullablelogeDelg[-0.28/0.13]? The abundance change due to a 1-sigma shift in log (surface gravity), {Delta}_g_phys.abund;arith.difffloatnullablelogeDelVt[-0.38/0.05]? The abundance change due to a 1-sigma shift in microturbulence, {Delta}_v_phys.abund;arith.difffloatnullablelogeDelM[-0.05/0.04]? The abundance change due to a 1-sigma shift in metallicity, {Delta}_M_phys.abund;arith.difffloatnullables_loge[0/0.5]? The total uncertainty in log(epsilon) abundance, S_X_stat.errorfloatnullable