期刊
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF JAPAN
卷 56, 期 6, 页码 1041-1057出版社
OXFORD UNIV PRESS
DOI: 10.1093/pasj/56.6.1041
关键词
galaxies : abundances; galaxies : dwarf; galaxies : individual (Ursa Minor); stars : abundances
With the HDS (High Dispersion Spectrograph) oil the Subaru Telescope. we obtained high-re volution optical region spectra of three red giant stars (COS 4. COS 82. and COS 347) in the Ursa Minor dwarf spheroidal galaxy. The chemical abundances in these stars were analyzed for 26 elements. including alpha-. iron-peak. and neutron-capture elements. All three stars show low abundances of alpha-elements (Mg, Si, and Ca). and two stars (COS 82 and COS 347) show high abundances of Mn compared to Galactic halo stars of similar metallicity. One star (COS 4) has been confirmed to be very metal deficient ([Fe/H] = -2.7) and found to show anomalously low abundances of Mn. Cu. and Ba. In another star, COS 82 ([Fe/H] = -1.5). we have found a large excess of heavy neutron-capture elements with a general abundance pattern similar to the scaled solar system r-process abundance curve. The-se observational results are rather puzzling: low abundances of a-elements and high abundance of Mn Seem to Suggest a significant contribution of SNe la at low metallicity, while there is no hint of ail s-process (i.e.. AGB Stars) contribution. even at [Fe/H] = -1.5. suggesting, a peculiar nucleosynthetic history of the UMi dSph galaxy.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据