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

Journal Article · Wed Mar 10 00:00:00 EST 2010 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/711/2/573· OSTI ID:21394350

Roederer, Ian U; Sneden, Christopher ^[1]; Thompson, Ian B; Preston, George W

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1. Department of Astronomy, University of Texas at Austin, 1 University Station, C1400, Austin, TX 78712-0259 (United States)

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.

• OSTI ID: 21394350
• Journal Information: Astrophysical Journal, Vol. 711, Issue 2; Other Information: DOI: 10.1088/0004-637X/711/2/573; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

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