New Nearby Hypervelocity Stars and Their Spatial Distribution from Gaia DR2
文献类型：期刊论文
| 作者 | Du,Cuihua1; Li,Hefan2; Yan,Yepeng2; Newberg,Heidi Jo3; Shi,Jianrong1,4 ; Ma,Jun1,4; Chen,Yuqin1,4; Wu,Zhenyu1,4
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| 刊名 | The Astrophysical Journal Supplement Series
 |
| 出版日期 | 2019-08-22 |
| 卷号 | 244期号:1 |
| 关键词 | Galaxy: center Galaxy: kinematics and dynamics Galaxy: stellar content |
| ISSN号 | 0067-0049 |
| DOI | 10.3847/1538-4365/ab328c |
| 英文摘要 | Abstract Based on about 4500 large tangential velocity (Vtan?>?0.75Vesc) with high-precision proper motions and 5σ parallaxes in Gaia data release 2 (DR2) 5D information derived from parallax and proper motion, we identify more than 600 high-velocity stars with a 50% unbound probability. Of these, 28 nearby (less than 6 kpc) late-type hypervelocity stars (HVSs) with over a 99% possibility of being unbound are discovered. In order to search for the unbound stars from the full Gaia DR2 6D phase space information derived from the parallax, proper motion, and radial velocity, we also identify 28 stars from the total velocity (Vgc?>?0.75Vesc) that have probabilities greater than 50% of being unbound from the Galaxy. Of these, only three have a nearly 99% probability of being unbound. In the whole HVSs subsample, there is 12 sources reported by other surveys. We study the spatial distribution of angular positions and angular separation of HVSs. We find the unbound HVSs are spatially anisotropic, which is most significant in the Galactic longitude at more than a 3σ level, and lower unbound probability HVSs are systematically more isotropic. The spatial distribution can reflect the origin of HVSs and we discuss the possible origin link with the anisotropy. |
| 语种 | 英语 |
| WOS记录号 | IOP:0067-0049-244-1-AB328C |
| 出版者 | The American Astronomical Society |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/27695]  |
| 专题 | 中国科学院国家天文台 |
| 作者单位 | 1.College of Astronomy and Space Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China; ducuihua@ucas.ac.cn 2.School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China 3.Department of Physics, Applied Physics and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA 4.Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012, People's Republic of China |
| 推荐引用方式 GB/T 7714 | Du,Cuihua,Li,Hefan,Yan,Yepeng,et al. New Nearby Hypervelocity Stars and Their Spatial Distribution from Gaia DR2[J]. The Astrophysical Journal Supplement Series,2019,244(1). |
| APA | Du,Cuihua.,Li,Hefan.,Yan,Yepeng.,Newberg,Heidi Jo.,Shi,Jianrong.,...&Wu,Zhenyu.(2019).New Nearby Hypervelocity Stars and Their Spatial Distribution from Gaia DR2.The Astrophysical Journal Supplement Series,244(1). |
| MLA | Du,Cuihua,et al."New Nearby Hypervelocity Stars and Their Spatial Distribution from Gaia DR2".The Astrophysical Journal Supplement Series 244.1(2019). |
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来源：国家天文台
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