The Hamburg/ESO R-process Enhanced Star survey (HERES) VII. Thorium abundances in metal-poor stars
文献类型：期刊论文
| 作者 | Ren, J.1,2,3 ; Christlieb, N.2; Zhao, G.1,4
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| 刊名 | ASTRONOMY & ASTROPHYSICS
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| 出版日期 | 2012 |
| 卷号 | 537 |
| 关键词 | stars: evolution stars: abundances galaxies: evolution Galaxy: halo stars: Population II Galaxy: abundances |
| 英文摘要 | We report thorium abundances for 77 metal-poor stars in the metallicity range of -3.5 < [Fe/H] < -1.0, based on "snapshot" spectra obtained with VLT-UT2/UVES during the HERES Survey. We were able to determine the thorium abundances with better than 1 sigma confidence for 17 stars, while for 60 stars we derived upper limits. For five stars common with previous studies, our results were in good agreement with the literature results. The thorium abundances span a wide range of about 4.0 dex, and scatter exists in the distribution of log (Th/Eu) ratios for lower metallicity stars, supporting previous studies suggesting the r-process is not universal. We derived ages from the log (Th/Eu) ratios for 12 stars, resulting in large scattered ages, and two stars with significant enhancement of Th relative to Eu are found, indicating the "actinide boost" does not seem to be a rare phenomenon and thus highlighting the risk in using log (Th/Eu) to derive stellar ages. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000300416800118 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/6302]  |
| 专题 | 国家天文台_光学天文研究部 |
| 作者单位 | 1.Shandong Univ Weihai, Sch Space Sci & Phys, Weihai 264209, Shandong, Peoples R China 2.Univ Heidelberg, Zentrum Astron, D-69117 Heidelberg, Germany 3.Uppsala Univ, Dept Phys & Astron, S-75120 Uppsala, Sweden 4.CAS, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China |
| 推荐引用方式 GB/T 7714 | Ren, J.,Christlieb, N.,Zhao, G.. The Hamburg/ESO R-process Enhanced Star survey (HERES) VII. Thorium abundances in metal-poor stars[J]. ASTRONOMY & ASTROPHYSICS,2012,537. |
| APA | Ren, J.,Christlieb, N.,&Zhao, G..(2012).The Hamburg/ESO R-process Enhanced Star survey (HERES) VII. Thorium abundances in metal-poor stars.ASTRONOMY & ASTROPHYSICS,537. |
| MLA | Ren, J.,et al."The Hamburg/ESO R-process Enhanced Star survey (HERES) VII. Thorium abundances in metal-poor stars".ASTRONOMY & ASTROPHYSICS 537(2012). |
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来源：国家天文台
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