J/ApJ/872/58ivo://CDS.VizieR/J/ApJ/872/58doi:10.26093/cds/vizier.18720058CDSHasselquist S.Carlin J.L.Holtzman J.A.Shetrone M.Hayes C.R.,Cunha K.Smith V.Beaton R.L.Sobeck J.Allende Prieto C.,Majewski S.R.Anguiano B.Bizyaev D.Garcia-Hernandez D.A.Lane R.R.,Pan K.Nidever D.L.Fernandez-Trincado J.G.Wilson J.C.Zamora O.2021-08-11T11:58:52Z2020-10-14T09:19:54ZCDS support team

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

cds-question@unistra.frgalaxiesspectroscopystellar-associationsinfrared-astronomyThe SDSS-IV Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey provides precise chemical abundances of 18 chemical elements for ~176000 red giant stars distributed over much of the Milky Way Galaxy (MW), and includes observations of the core of the Sagittarius dwarf spheroidal galaxy (Sgr). The APOGEE chemical abundance patterns of Sgr have revealed that it is chemically distinct from the MW in most chemical elements. We employ a k-means clustering algorithm to six-dimensional chemical space defined by [(C+N)/Fe], [O/Fe], [Mg/Fe], [Al/Fe], [Mn/Fe], and [Ni/Fe] to identify 62 MW stars in the APOGEE sample that have Sgr-like chemical abundances. Of the 62 stars, 35 have Gaia kinematics and positions consistent with those predicted by N-body simulations of the Sgr stream, and are likely stars that have been stripped from Sgr during the last two pericenter passages (<2Gyr ago). Another 20 of the 62 stars exhibit chemical abundances indistinguishable from the Sgr stream stars, but are on highly eccentric orbits with median rapo ~25kpc. These stars are likely the "accreted" halo population thought to be the result of a separate merger with the MW 8-11 Gyr ago. We also find one hypervelocity star candidate. We conclude that Sgr was enriched to [Fe/H]~-0.2 before its most recent pericenter passage. If the "accreted halo" population is from one major accretion event, then this progenitor galaxy was enriched to at least [Fe/H]~-0.6, and had a similar star formation history to Sgr before merging.2019ApJ...872...58Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/872/58CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)III/284 : APOGEE-2 data from DR16 (Majewski+, 2017)I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)I/345 : Gaia DR2 (Gaia Collaboration, 2018)J/ApJ/670/346 : M giant stars in the Sgr dwarf galaxy. V. (Chou+, 2007)J/ApJ/749/77 : MW halo. III. Statistical abundances (Schlaufman+, 2012)J/ApJ/779/102 : Metallicities of RGB stars in dwarf galaxies (Kirby+, 2013)J/ApJ/778/149 : Abundances for 3 stars in Sgr dSph (McWilliam+, 2013)J/A+A/568/A7 : Model SDSS colors for halo stars (Allende Prieto+, 2014)J/A+A/577/A81 : Deep SDSS Optical Spectroscopy. II. (Fernandez-Alvar+, 2015)J/ApJ/808/16 : Cannon: a new approach to determine abundances (Ness+, 2015)J/ApJS/221/24 : SDSS-III APOGEE H-band spectral line lists (Shetrone+, 2015)J/AJ/151/144 : ASPCAP weights for APOGEE chemical elements (Garcia+, 2016)J/ApJ/823/59 : WISE and 2MASS photometry of M giant stars (Li+, 2016)J/ApJ/850/96 : PS1 3{pi} RRab stars within Sgr stream (Hernitschek+, 2017)J/MNRAS/465/501 : APOGEE N-rich stars in inner Galaxy (Schiavon+, 2017)J/ApJ/855/83 : Abundances of very metal-poor stars in Sgr (Hansen+, 2018)J/ApJ/852/49 : Properties of metal-poor stars in APOGEE DR13 (Hayes+, 2018)J/AJ/156/126 : Stellar abundances from BACCHUS analysis (Jonsson+, 2018)J/ApJ/889/63 : Properties of Sgr Stars (Hayes+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/872/58https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/872/58http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/872/58https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/872/58https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/872/58http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/872/58GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/872/58/table1 (The Sagittarius dwarf spheroidal galaxy (Sgr) stream cluster)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/872/58/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/872/58/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/872/58/table1?GETtext/xml+votable180.050000true3.8051830556-14.50782611110.005555555555555556Cone search capability for table J/ApJ/872/58/table2 ("Low-Mg" population (LMg) cluster (see Section 5.1))https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/872/58/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/872/58/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/872/58/table2?GETtext/xml+votable180.050000true2.4847467.65557888890.0055555555555555566/77 88 90 101 167 176 178 339 1121 1459 1883 1893 1977 2872 3464 3757 3758 4015 4129 4680 4826 5360 5367 5493 5570 5960 5972 5980 6396 7680 8331 8873 8964 8965 8972 9015 9040 9251 9266 9355 9363 9372 9431 9621 9633 9705 9787 9805 9828 9858 9986 10095 10224 10314 10323 10603 10606 10662 10705 10929 10941 10949 10962 10977 10980 10981 11192 11216 11400 11407 11414 12032 12272 12387 12404 12918 12951 14524 14773 14774 14922 14934 14958 15041 15045 15057 15104 15146 15160 16244 16883 16979 16981 17174 17218 17792 17793 17799 19012 19013 19627 21698 22860 23207 23668 23860 23914 24009 24033 24274 24282 24283 24305 25402 25406 25624 25854 25875 25880 26015 26020 26023 26072 26112 26166 26178 26247 26254 26276 26277 26604 26677 26890 26915 27072 27125 27132 27633 27641 27667 27670 27679 27859 27861 27901 27902 27908 27911 27917 27947 28066 28125 28202 28247 28289 28297 28327 28372 28618 28622 28779 28781 28783 28820 28826 28844 28848 28888 28909 28910 28912 28952 29118 29187 29191 29199 29206 29299 29327 29441 29753 29828 29840 30031 30034 30040 30044 30046 30203 31144 31410 31581 32156 32452 32460 32501 32747 36784 40742 45024 48035 48040 48042 48044 48046https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/872/58?format=asciiInfrareddefaultJ/ApJ/872/58/table1The Sagittarius dwarf spheroidal galaxy (Sgr) stream clusterrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDAPOGEE identifier (2MHHMMSSss+DDMMSSs; J2000)meta.id;meta.maincharMmMembership code (1)meta.code.membercharRapo[0.87/762.97] Apo-center radius relative to the Galactic centerkpcphys.size.radiusfloatE_Rapo[0.34/350.66] Upper uncertainty in Rapokpcstat.error;stat.maxfloate_Rapo[0.09/239.41] Lower uncertainty in Rapokpcstat.errorfloatecc[0.07/0.98] Eccentricitysrc.orbital.eccentricityfloatE_ecc[0.0/0.61] Upper uncertainty in eccstat.error;stat.maxfloate_ecc[0.0/0.58] Lower uncertainty in eccstat.errorfloat2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from APOGEE-2 DR6 (Cat. III/284) (right ascension part)degpos.eq.ra;meta.main_DEPositions from APOGEE-2 DR6 (Cat. III/284) (declination part)degpos.eq.dec;meta.mainJ/ApJ/872/58/table2"Low-Mg" population (LMg) cluster (see Section 5.1)recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDAPOGEE identifier (2MHHMMSSss+DDMMSSs; J2000)meta.id;meta.maincharRapo[0.95/110.8] Apo-center radius relative to the Galactic centerkpcphys.size.radiusfloatecc[0.09/0.99] Eccentricitysrc.orbital.eccentricityfloat2MDisplay the 2MASS data (Cutri et al. 2003, Cat. II/246)meta.ref.urlcharSimbadSimbad column added by the CDSmeta.ref.urlchar_RAPositions from APOGEE-2 DR6 (Cat. III/284) (right ascension part)degpos.eq.ra;meta.main_DEPositions from APOGEE-2 DR6 (Cat. III/284) (declination part)degpos.eq.dec;meta.main