Evidence for the accretion origin of halo stars with an extreme r-process enhancement
文献类型:期刊论文
作者 | Xing, Qian-Fan2![]() ![]() |
刊名 | NATURE ASTRONOMY
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出版日期 | 2019-07-01 |
卷号 | 3期号:7页码:631-635 |
ISSN号 | 2397-3366 |
DOI | 10.1038/s41550-019-0764-5 |
英文摘要 | Small stellar systems such as dwarf galaxies are suggested to be the main building blocks of our Galaxy according to numerical simulations(1) in Lambda cold dark matter models and observational support for this hypothesis comes from the existence of stellar streams such as the Sagittarius tidal stream(2). However, it is unclear how many and what kind of stars in our Galaxy originate from satellite dwarf galaxies, something that could be constrained by analysing chemical abundances of metal-poor stars. Here we report on the discovery of a metal-poor star with an extreme r-process enhancement and alpha-element deficiency. In this star, the abundance ratio of the r-process element Eu with respect to Fe is more than one order of magnitude larger than the Sun and the metallicity is 1/20 of solar metallicity. Stars like this one have been found in present-day dwarf galaxies, providing the clearest chemical signature of past accretion events onto the Milky Way. The long timescale of chemical evolution of the host dwarf galaxy expected from the abundance of alpha-elements with respect to Fe suggests that the accretion occurred in a relatively late phase compared with most of the accretions that formed the bulk of the Milky Way halo. |
WOS关键词 | METAL-POOR STARS ; ABUNDANCE RATIOS ; DWARF GALAXIES ; ENRICHMENT ; EVOLUTION ; GIANT |
资助项目 | National Natural Science Foundation of China[11890694] ; National Natural Science Foundation of China[11390371] ; National Natural Science Foundation of China[11603033] ; National Natural Science Foundation of China[11573032] ; National Natural Science Foundation of China[11773033] ; JSPS-CAS Joint Research Program ; JSPS KAKENHI[17K14249] ; JSPS KAKENHI[16H02168] ; Chinese NDRC |
WOS研究方向 | Astronomy & Astrophysics |
语种 | 英语 |
WOS记录号 | WOS:000474405800019 |
出版者 | NATURE PUBLISHING GROUP |
资助机构 | National Natural Science Foundation of China ; National Natural Science Foundation of China ; JSPS-CAS Joint Research Program ; JSPS-CAS Joint Research Program ; JSPS KAKENHI ; JSPS KAKENHI ; Chinese NDRC ; Chinese NDRC ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; JSPS-CAS Joint Research Program ; JSPS-CAS Joint Research Program ; JSPS KAKENHI ; JSPS KAKENHI ; Chinese NDRC ; Chinese NDRC ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; JSPS-CAS Joint Research Program ; JSPS-CAS Joint Research Program ; JSPS KAKENHI ; JSPS KAKENHI ; Chinese NDRC ; Chinese NDRC ; National Natural Science Foundation of China ; National Natural Science Foundation of China ; JSPS-CAS Joint Research Program ; JSPS-CAS Joint Research Program ; JSPS KAKENHI ; JSPS KAKENHI ; Chinese NDRC ; Chinese NDRC |
源URL | [http://ir.bao.ac.cn/handle/114a11/26963] ![]() |
专题 | 中国科学院国家天文台 |
通讯作者 | Xing, Qian-Fan; Zhao, Gang |
作者单位 | 1.Univ Hyogo, Ctr Astron, Sayo, Japan 2.Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing, Peoples R China 3.Natl Astron Observ Japan, Tokyo, Japan 4.Grad Univ Adv Studies SOKENDAI, Sch Phys Sci, Dept Astron Sci, Tokyo, Japan 5.Univ Tokyo, Kavli Inst Phys & Math Universe, Kashiwa, Chiba, Japan |
推荐引用方式 GB/T 7714 | Xing, Qian-Fan,Zhao, Gang,Aoki, Wako,et al. Evidence for the accretion origin of halo stars with an extreme r-process enhancement[J]. NATURE ASTRONOMY,2019,3(7):631-635. |
APA | Xing, Qian-Fan.,Zhao, Gang.,Aoki, Wako.,Honda, Satoshi.,Li, Hai-Ning.,...&Matsuno, Tadafumi.(2019).Evidence for the accretion origin of halo stars with an extreme r-process enhancement.NATURE ASTRONOMY,3(7),631-635. |
MLA | Xing, Qian-Fan,et al."Evidence for the accretion origin of halo stars with an extreme r-process enhancement".NATURE ASTRONOMY 3.7(2019):631-635. |
入库方式: OAI收割
来源:国家天文台
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