THE [Fe/H], [C/Fe], AND [α/Fe] DISTRIBUTIONS OF THE BOÖTES I DWARF SPHEROIDAL GALAXY
THE [Fe/H], [C/Fe], AND [α/Fe] DISTRIBUTIONS OF THE BOÖTES I DWARF SPHEROIDAL GALAXY
复制标题
牧夫座 I 矮椭球星系的 [Fe/H]、[C/Fe] 和 [α/Fe] 分布
DOI：
10.1088/0004-637x/738/1/51
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发表时间：
2011
期刊：
影响因子：
--
通讯作者：
C. Rockosi
中科院分区：
文献类型：
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作者：
David K. Lai;Y. S. Lee;M. Bolte;S. Lucatello;T. Beers;Jennifer A. Johnson;T. Sivarani;C. Rockosi
We present the results of a low-resolution spectral abundance study of 25 stars in the Boötes I dwarf spheroidal (dSph) galaxy. The data were obtained with the low resolution imaging spectrometer instrument at Keck Observatory and allow us to measure [Fe/H], [C/Fe], and [α/Fe] for each star. We find both a large spread in metallicity (2.1 dex in [Fe/H]) as well as a low average metallicity in this system, 〈[Fe/H]〉 = −2.59, matching previous estimates. This sample includes a newly discovered extremely metal-poor star, with [Fe/H] = −3.8, that is one of the most metal-poor stars yet found in a dSph. We compare the metallicity distribution function of Boötes I to analytic chemical evolution models. While the metallicity distribution function of Boötes I is best fit by an Extra Gas chemical evolution model, leaky-box models also provide reasonable fits. We also find that the [α/Fe] distribution and the carbon-enhanced metal-poor fraction of our sample (12%) are reasonable matches to Galactic halo star samples in the same metallicity range, indicating that at these low metallicities, systems like the Boötes I ultra-faint dSph could have been contributors to the Galactic halo.
DOI：
10.1086/590336
发表时间：
2008-05
期刊：
The Astrophysical Journal
影响因子：
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作者：
N. Martin;J. D. de Jong;H. Rix
通讯作者：
N. Martin;J. D. de Jong;H. Rix