Discovery of a Candidate Hypervelocity Star Originating from the Sagittarius Dwarf Spheroidal Galaxy
文献类型：期刊论文
| 作者 | Huang,Yang1; Li,Qingzheng2,3; Zhang,Huawei4,5; Li,Xinyi1; Sun,Weixiang1; Chang,Jiang6,7; Dong,Xiaobo2; Liu,Xiaowei1 |
| 刊名 | The Astrophysical Journal Letters
 |
| 出版日期 | 2021-02-01 |
| 卷号 | 907期号:2 |
| 关键词 | Hypervelocity stars Galaxy kinematics Sagittarius dwarf spheroidal galaxy Galaxy stellar halos Chemical abundances |
| ISSN号 | 2041-8205 |
| DOI | 10.3847/2041-8213/abd413 |
| 英文摘要 | Abstract In this Letter, we report the discovery of an intriguing hypervelocity star (HVS; J1443+1453) candidate that is probably from the Sagittarius Dwarf Spheroidal galaxy (Sgr dSph). The star is an old and very metal-poor low-mass main-sequence turn-off star (age ～14.0 Gyr and [Fe/H]?=??2.23 dex) and has a total velocity of km s?1 in the Galactic rest frame and a heliocentric distance of kpc. The velocity of J1443+1453 is larger than the escape speed at its position, suggesting that it is a promising HVS candidate. By reconstructing its trajectory in the Galactic potential, we find that the orbit of J1443+1453 intersects closely with that of Sgr dSph Myr ago, when the latter has its latest pericentric passage through the Milky Way. The encounter occurs at a distance kpc from the center of Sgr dSph, a distance that is smaller than the size of the Sgr dSph. The chemical properties of this star are also consistent with those of an Sgr dSph-associated globular cluster, or of the Sgr stream member stars. Our finding suggests that J1443+1453 is an HVS that is either tidally stripped from the Sgr dSph or ejected from the Sgr dSph by the gravitational slingshot effect, requiring a (central) massive/intermediate-mass black hole or a (central) massive primordial black hole in the Sgr dSph. |
| 语种 | 英语 |
| WOS记录号 | IOP:2041-8205-907-2-ABD413 |
| 出版者 | The American Astronomical Society |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/60707]  |
| 专题 | 中国科学院国家天文台 |
| 通讯作者 | Huang,Yang |
| 作者单位 | 1.South-Western Institute for Astronomy Research, Yunnan University, Kunming 650500, People’s Republic of China; yanghuang@ynu.edu.cn, x.liu@ynu.edu.cn 2.Yunnan Observatories, Chinese Academy of Sciences, Kunming 650011, People’s Republic of China; liqingzheng@ynao.ac.cn 3.University of Chinese Academy of Sciences, Beijing 100049, People’s Republic of China 4.Department of Astronomy, School of Physics, Peking University, Beijing 100871, People’s Republic of China 5.Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871, People’s Republic of China 6.Key Lab of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People’s Republic of China 7.Purple Mountain Observatory, Chinese Academy of Sciences, Nanjing 210034, People’s Republic of China |
| 推荐引用方式 GB/T 7714 | Huang,Yang,Li,Qingzheng,Zhang,Huawei,et al. Discovery of a Candidate Hypervelocity Star Originating from the Sagittarius Dwarf Spheroidal Galaxy[J]. The Astrophysical Journal Letters,2021,907(2). |
| APA | Huang,Yang.,Li,Qingzheng.,Zhang,Huawei.,Li,Xinyi.,Sun,Weixiang.,...&Liu,Xiaowei.(2021).Discovery of a Candidate Hypervelocity Star Originating from the Sagittarius Dwarf Spheroidal Galaxy.The Astrophysical Journal Letters,907(2). |
| MLA | Huang,Yang,et al."Discovery of a Candidate Hypervelocity Star Originating from the Sagittarius Dwarf Spheroidal Galaxy".The Astrophysical Journal Letters 907.2(2021). |
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