METALLICITY GRADIENTS OF THICK DISK DWARF STARS
文献类型：期刊论文
| 作者 | Carrell, Kenneth; Chen, Yuqin ; Zhao, Gang
|
| 刊名 | ASTRONOMICAL JOURNAL
 |
| 出版日期 | 2012-12-01 |
| 卷号 | 144期号:6 |
| 关键词 | Galaxy: abundances Galaxy: disk |
| 英文摘要 | We examine the metallicity distribution of the Galactic thick disk using F, G, and K dwarf stars selected from the Sloan Digital Sky Survey, Data Release 8. Using the large sample of dwarf stars with proper motions and spectroscopically determined stellar parameters, metallicity gradients in the radial direction for various heights above the Galactic plane and in the vertical direction for various radial distances from the Galaxy center have been found. In particular, we find a vertical metallicity gradient of -0.113 +/- 0.010 (-0.125 +/- 0.008) dex kpc(-1) using an isochrone (photometric) distance determination in the range 1 kpc < vertical bar Z vertical bar < 3 kpc, which is the vertical height range most consistent with the thick disk of our Galaxy. In the radial direction, we find metallicity gradients between +0.02 and +0.03 dex kpc(-1) for bins in the vertical direction between 1 kpc < vertical bar Z vertical bar < 3 kpc. Both of these results agree with similar values determined from other populations of stars, but this is the first time a radial metallicity gradient for the thick disk has been found at these vertical heights. We are also able to separate thin and thick disk stars based on kinematic and spatial probabilities in the vertical height range where there is significant overlap of these two populations. This should aid further studies of the metallicity gradients of the disk for vertical heights lower than those studied here but above the solar neighborhood. Metallicity gradients in the thin and thick disks are important probes into possible formation scenarios for our Galaxy and a consistent picture is beginning to emerge from results using large spectroscopic surveys, such as the ones presented here. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000311165400028 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/6349]  |
| 专题 | 国家天文台_光学天文研究部 |
| 作者单位 | Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China |
| 推荐引用方式 GB/T 7714 | Carrell, Kenneth,Chen, Yuqin,Zhao, Gang. METALLICITY GRADIENTS OF THICK DISK DWARF STARS[J]. ASTRONOMICAL JOURNAL,2012,144(6). |
| APA | Carrell, Kenneth,Chen, Yuqin,&Zhao, Gang.(2012).METALLICITY GRADIENTS OF THICK DISK DWARF STARS.ASTRONOMICAL JOURNAL,144(6). |
| MLA | Carrell, Kenneth,et al."METALLICITY GRADIENTS OF THICK DISK DWARF STARS".ASTRONOMICAL JOURNAL 144.6(2012). |
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来源：国家天文台
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