THE METALLICITY GRADIENT OF THE THICK DISK BASED ON RED HORIZONTAL-BRANCH STARS FROM SDSS DR8
文献类型：期刊论文
| 作者 | Chen, Y. Q.; Zhao, G. ; Carrell, K.; Zhao, J. K.
|
| 刊名 | ASTRONOMICAL JOURNAL
 |
| 出版日期 | 2011-12-01 |
| 卷号 | 142期号:6 |
| 关键词 | Galaxy: disk Galaxy: kinematics and dynamics Galaxy: structure stars: horizontal-branch stars: late-type |
| 英文摘要 | Based on SDSS DR8, we have selected a sample of 1728 red horizontal-branch (RHB) stars with vertical bar Z vertical bar < 3 kpc by using a color-metallicity relation and stellar parameters. The sample stars clearly trace a typical thick disk population with peaks at vertical bar Z vertical bar = 1.26 kpc and [Fe/H] = -0.54. The vertical metallicity gradient of the thick disk is estimated in two ways. One is a fit to the Gaussian peaks of the metallicity histograms of the thick disk by subtracting minor contributions from the thin disk and the inner halo based on the Besan, con Galaxy Model. The resulting gradient is -0.12 +/- 0.01 dex kpc(-1) for 0.5 < vertical bar Z vertical bar < 3 kpc. The other method is to linearly fit the data based on stars with 1 < vertical bar Z vertical bar < 3 kpc being the main component of the thick disk. Five subgroups are then selected in different directions in the X-vertical bar Z vertical bar plane to investigate the difference in the vertical metallicity gradient between the Galactocenter and anti-Galactocenter directions. We found that a vertical gradient of -0.22 +/- 0.07 dex kpc(-1) is detected for five directions except for one involving the pollution of stars from the bulge. The results indicate that the vertical gradient is dominant, but a radial gradient has a minor contribution for the thick disk population represented by RHB stars with 1 < vertical bar Z vertical bar < 3 kpc. The present work strongly suggests the existence of a metallicity gradient in the thick disk, which is thought to be negligible in most previous works in the literature. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000297254500006 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/8010]  |
| 专题 | 国家天文台_光学天文研究部 |
| 作者单位 | Chinese Acad Sci, Key Lab Opt Astron, Natl Astron Observ, Beijing 100012, Peoples R China |
| 推荐引用方式 GB/T 7714 | Chen, Y. Q.,Zhao, G.,Carrell, K.,et al. THE METALLICITY GRADIENT OF THE THICK DISK BASED ON RED HORIZONTAL-BRANCH STARS FROM SDSS DR8[J]. ASTRONOMICAL JOURNAL,2011,142(6). |
| APA | Chen, Y. Q.,Zhao, G.,Carrell, K.,&Zhao, J. K..(2011).THE METALLICITY GRADIENT OF THE THICK DISK BASED ON RED HORIZONTAL-BRANCH STARS FROM SDSS DR8.ASTRONOMICAL JOURNAL,142(6). |
| MLA | Chen, Y. Q.,et al."THE METALLICITY GRADIENT OF THE THICK DISK BASED ON RED HORIZONTAL-BRANCH STARS FROM SDSS DR8".ASTRONOMICAL JOURNAL 142.6(2011). |
入库方式： OAI收割
来源：国家天文台
浏览0
下载0
收藏0
其他版本
除非特别说明，本系统中所有内容都受版权保护，并保留所有权利。