THE KINEMATICS AND CHEMISTRY OF RED HORIZONTAL BRANCH STARS IN THE SAGITTARIUS STREAMS
文献类型：期刊论文
| 作者 | Shi, W. B.1,2; Chen, Y. Q.1; Carrell, K.1; Zhao, G.1,2
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| 刊名 | ASTROPHYSICAL JOURNAL
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| 出版日期 | 2012-06-01 |
| 卷号 | 751期号:2 |
| 关键词 | galaxies: dwarf Galaxy: halo stars: abundances |
| 英文摘要 | We have selected 556 red horizontal branch stars along the streams of the Sagittarius (Sgr) dwarf galaxy from Sloan Digital Sky Survey DR7 spectroscopic data using a theoretical model. The metallicity and alpha-element distributions are investigated for stars in the Sgr streams and for Galactic stars at the same locations. We find that the Sgr stars have two peaks in the metallicity distribution while the Galactic stars have a more prominent metal-poor peak. Meanwhile, [alpha/Fe] ratios of the Sgr stars are lower than those of the Galactic stars. Among the Sgr stars, we find a difference in the metallicity distribution between the leading and trailing arms of the Sgr tidal tails. The metallicity and [alpha/Fe] distribution of the leading arm is similar to that of the Galaxy. The trailing arm is composed mainly of a metal-rich component and [alpha/Fe] is obviously lower than that of the Galactic stars. The metallicity gradient is -(1.8 +/- 0.3) x10(-3) dex deg(-1) in the first wrap of the trailing arm and -(1.5 +/- 0.4) x10(-3) dex deg(-1) in the first wrap of the leading arm. No significant gradient exists along the second wraps of the leading or trailing arms. It seems that the Sgr dwarf galaxy initially lost the metal-poor component in the second wrap (older) arms due to the tidal force of our Galaxy and then the metal-rich component is disrupted in the first wrap (younger) arms. Finally, we found that the velocity dispersion of the trailing arm from 88 degrees < Lambda(circle dot) < 112 degrees is sigma = 9.808 +/- 1.0 km s(-1), which is consistent with previous work in the literature. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000304204600051 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/6279]  |
| 专题 | 国家天文台_光学天文研究部 |
| 作者单位 | 1.Chinese Acad Sci, Key Lab Opt Astron, Natl Astron Observ, Beijing 100012, Peoples R China 2.Shandong Univ Weihai, Shandong Prov Key Lab Opt Astron & Solar Terr Env, Sch Space Sci & Phys, Weihai 264209, Peoples R China |
| 推荐引用方式 GB/T 7714 | Shi, W. B.,Chen, Y. Q.,Carrell, K.,et al. THE KINEMATICS AND CHEMISTRY OF RED HORIZONTAL BRANCH STARS IN THE SAGITTARIUS STREAMS[J]. ASTROPHYSICAL JOURNAL,2012,751(2). |
| APA | Shi, W. B.,Chen, Y. Q.,Carrell, K.,&Zhao, G..(2012).THE KINEMATICS AND CHEMISTRY OF RED HORIZONTAL BRANCH STARS IN THE SAGITTARIUS STREAMS.ASTROPHYSICAL JOURNAL,751(2). |
| MLA | Shi, W. B.,et al."THE KINEMATICS AND CHEMISTRY OF RED HORIZONTAL BRANCH STARS IN THE SAGITTARIUS STREAMS".ASTROPHYSICAL JOURNAL 751.2(2012). |
入库方式： OAI收割
来源：国家天文台
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