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Title: CHARACTERIZING THE CHEMISTRY OF THE MILKY WAY STELLAR HALO: DETAILED CHEMICAL ANALYSIS OF A METAL-POOR STELLAR STREAM ,

We present the results of a detailed abundance analysis of one of the confirmed building blocks of the Milky Way stellar halo, a kinematically coherent metal-poor stellar stream. We have obtained high-resolution and high signal-to-noise spectra of 12 probable stream members using the Magellan Inamori Kyocera Echelle spectrograph on the Magellan-Clay Telescope at Las Campanas Observatory and the 2dCoude spectrograph on the Smith Telescope at McDonald Observatory. We have derived abundances or upper limits for 51 species of 46 elements in each of these stars. The stream members show a range of metallicity (-3.4 < [Fe/H] <-1.5) but are otherwise chemically homogeneous, with the same star-to-star dispersion in [X/Fe] as the rest of the halo. This implies that, in principle, a significant fraction of the Milky Way stellar halo could have formed from accreted systems like the stream. The stream stars show minimal evolution in the alpha or Fe-group elements over the range of metallicity. This stream is enriched with material produced by the main and weak components of the rapid neutron-capture process and shows no evidence for enrichment by the slow neutron-capture process.
Authors:
;  [1] ; ; ;  [2]
  1. Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712-0259 (United States)
  2. Carnegie Observatories, 813 Santa Barbara Street, Pasadena, CA 91101 (United States)
Publication Date:
OSTI Identifier:
21394350
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 711; Journal Issue: 2; Other Information: DOI: 10.1088/0004-637X/711/2/573
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; CHEMICAL ANALYSIS; METALS; MILKY WAY; NEUTRON REACTIONS; NUCLEOSYNTHESIS; SLOW NEUTRONS; STARS; TELESCOPES BARYON REACTIONS; BARYONS; ELEMENTARY PARTICLES; ELEMENTS; FERMIONS; GALAXIES; HADRON REACTIONS; HADRONS; NEUTRONS; NUCLEAR REACTIONS; NUCLEON REACTIONS; NUCLEONS; SYNTHESIS