Non-LTE analysis of the sodium abundance of metal-poor stars in the galactic disk and halo
文献类型:期刊论文
作者 | Takeda, Y; Zhao, G![]() ![]() ![]() ![]() |
刊名 | CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS
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出版日期 | 2003-08-01 |
卷号 | 3期号:4页码:316-340 |
关键词 | galaxy : evolution radiative transfer stars : abundances stars : atmospheres stars : late-type |
英文摘要 | We performed an extensive non-LTE analysis of the neutral sodium lines of Na 1 5683/5688, 5890/5896, 6154/6161, and 8183/8195 in disk/halo stars of types F-K covering a wide metallicity range (-4 less than or similar to [Fe/H] less than or similar to +0.4), using our own data as well as data collected from the literature. For comparatively metal-rich disk stars (-1 less than or similar to [Fe/H] less than or similar to +0.4) where the weaker 6154/6161 lines are the best abundance indicators, we confirmed [Na/Fe] similar to 0 with an "upturn" (i.e., a shallow/broad dip around -0.5 less than or similar to [Fe/H] less than or similar to 0) as already reported in previous studies. For the metal-deficient halo stars, where the much stronger 5890/5896 or 8183/8195 lines subject to considerable (negative) non-LTE corrections amounting to 0.5 dex have to be used, our analysis suggests mildly "subsolar" [Na/Fe] values down to similar to -0.4 (with a somewhat large scatter of similar to +/-0.2 dex) on the average at the typical halo metallicity of [Fe/H] similar to -2, followed by a rise again to a near-solar ratio of [Na/Fe] similar to 0 at the very metal-poor regime [Fe/H] similar to -3 to -4. These results are discussed in comparison with the previous observational studies along with the theoretical predictions from the available chemical evolution models. |
收录类别 | SCI |
语种 | 英语 |
WOS记录号 | WOS:000184993900003 |
源URL | [http://ir.bao.ac.cn/handle/114a11/8474] ![]() |
专题 | 国家天文台_光学天文研究部 |
作者单位 | 1.Komazawa Univ, Setagaya Ku, Tokyo 1548525, Japan 2.Chinese Acad Sci, Natl Astron Observ, Beijing 100012, Peoples R China 3.Tokai Univ, Liberal Arts Educ Ctr, Hiratsuka, Kanagawa 2591292, Japan 4.Tokai Univ, Fac Sci, Dept Phys, Kanagawa 2591292, Japan 5.Peking Univ, Sch Phys, Dept Astron, Beijing 100871, Peoples R China 6.Peking Univ, CAS, Joint Beijing Astrophys Ctr, Beijing 100871, Peoples R China |
推荐引用方式 GB/T 7714 | Takeda, Y,Zhao, G,Takada-Hidai, M,et al. Non-LTE analysis of the sodium abundance of metal-poor stars in the galactic disk and halo[J]. CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,2003,3(4):316-340. |
APA | Takeda, Y.,Zhao, G.,Takada-Hidai, M.,Chen, YQ.,Saito, Y.,...&Zhao Gang.(2003).Non-LTE analysis of the sodium abundance of metal-poor stars in the galactic disk and halo.CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS,3(4),316-340. |
MLA | Takeda, Y,et al."Non-LTE analysis of the sodium abundance of metal-poor stars in the galactic disk and halo".CHINESE JOURNAL OF ASTRONOMY AND ASTROPHYSICS 3.4(2003):316-340. |
入库方式: OAI收割
来源:国家天文台
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