Multiple Stellar Populations at Less-evolved Stages: Detection of Chemical Variations among Main-sequence Dwarfs in NGC 1978
文献类型：期刊论文
| 作者 | Li,Chengyuan1; Tang,Baitian1; Milone,Antonino P.2,10; de Grijs,Richard7,8,9; Hong,Jongsuk5,6; Yang,Yujiao4,9; Wang,Yue3
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| 刊名 | The Astrophysical Journal
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| 出版日期 | 2021 |
| 卷号 | 906期号:2 |
| 关键词 | Stellar populations Star clusters Large Magellanic Cloud Hertzsprung Russell diagram G dwarf stars M dwarf stars |
| ISSN号 | 0004-637X |
| DOI | 10.3847/1538-4357/abc8f2 |
| 英文摘要 | Abstract Multiple stellar populations (MPs) with different chemical compositions are not exclusive features of old globular clusters (older than 10 Gyr). Indeed, recent studies reveal that younger clusters (～2–6 Gyr-old) in the Magellanic Clouds also exhibit star-to-star chemical variations among evolved stars. However, whether MPs are present among less-evolved dwarfs of these intermediate-age clusters is still unclear. In this work, we search for chemical variations among GK-type dwarfs in the ～2 Gyr old cluster NGC 1978, which is the youngest cluster with MPs. We exploit deep ultraviolet and visual observations from the Hubble Space Telescope to constrain the nitrogen (N) and oxygen (O) variations among main-sequence (MS) stars. To do this, we compare appropriate photometric diagrams that are sensitive to N and O with synthetic diagrams of simple stellar populations and MPs. We conclude that the G- and K-type MS stars in NGC 1978 host MPs. Our statistical analysis shows that the fraction of N-rich stars ranges from ～40% to ～80%, depending on the detailed distributions of N and O. |
| 语种 | 英语 |
| WOS记录号 | IOP:0004-637X-906-2-ABC8F2 |
| 出版者 | The American Astronomical Society |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/60931]  |
| 专题 | 中国科学院国家天文台 |
| 通讯作者 | Li,Chengyuan |
| 作者单位 | 1.School of Physics and Astronomy, Sun Yat-sen University, Daxue Road, Zhuhai, 519082, People's Republic of China; lichengy5@mail.sysu.edu.cn 2.Dipartimento di Fisica e Astronomia “Galileo Galilei,” Univ. di Padova, Vicolo dell’Osservatorio 3, Padova, I-35122, Italy 3.Key Laboratory for Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Beijing 100101, People's Republic of China 4.Department of Astronomy, School of Physics, Peking University, Yi He Yuan Lu 5, Haidian District, Beijing 100871, People's Republic of China 5.Department of Astronomy, Yonsei University 50 Yonsei-Ro, Seodaemun-Gu, Seoul, Republic Of Korea 6.Korea Astronomy and Space Science Institute, Daejeon 34055, Republic Of Korea 7.International Space Science Institute–Beijing, 1 Nanertiao, Zhongguancun, Hai Dian District, Beijing 100190, People's Republic of China 8.Research Centre for Astronomy, Astrophysics and Astrophotonics, Macquarie University, Balaclava Road, Sydney, NSW 2109, Australia 9.Department of Physics and Astronomy, Macquarie University, Balaclava Road, Sydney, NSW 2109, Australia 10.Istituto Nazionale di Astrofisica—Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova, I-35122, Italy |
| 推荐引用方式 GB/T 7714 | Li,Chengyuan,Tang,Baitian,Milone,Antonino P.,et al. Multiple Stellar Populations at Less-evolved Stages: Detection of Chemical Variations among Main-sequence Dwarfs in NGC 1978[J]. The Astrophysical Journal,2021,906(2). |
| APA | Li,Chengyuan.,Tang,Baitian.,Milone,Antonino P..,de Grijs,Richard.,Hong,Jongsuk.,...&Wang,Yue.(2021).Multiple Stellar Populations at Less-evolved Stages: Detection of Chemical Variations among Main-sequence Dwarfs in NGC 1978.The Astrophysical Journal,906(2). |
| MLA | Li,Chengyuan,et al."Multiple Stellar Populations at Less-evolved Stages: Detection of Chemical Variations among Main-sequence Dwarfs in NGC 1978".The Astrophysical Journal 906.2(2021). |
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来源：国家天文台
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