Identifying Galactic Halo Substructure in 6D Phase Space Using ～13,000 LAMOST K Giants
文献类型：期刊论文
| 作者 | Yang,Chengqun3,4; Xue,Xiang-Xiang4; Li,Jing1,2; Zhang,Lan4 ; Liu,Chao3,4; Zhao,Gang3,4; Chang,Jiang4; Tian,Hao4; Li,Chengdong3,4
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| 刊名 | The Astrophysical Journal
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| 出版日期 | 2019-07-25 |
| 卷号 | 880期号:1 |
| 关键词 | Galaxy: evolution Galaxy: formation Galaxy: halo Galaxy: kinematics and dynamics |
| ISSN号 | 0004-637X |
| DOI | 10.3847/1538-4357/ab2462 |
| 英文摘要 | Abstract We construct a large halo K-giant sample by combining the positions, distances, radial velocities, and metallicities of over 13,000 LAMOST DR5 halo K giants with the Gaia DR2 proper motions, which covers a Galactocentric distance range of 5–120 kpc. Using a position–velocity clustering estimator (the 6Distance), we statistically quantify the presence of position–velocity substructure at high significance: K giants have more close pairs in position–velocity space than a smooth stellar halo. We find that the amount of substructure in the halo increases with increasing distance and metallicity. With a percolation algorithm named friends-of-friends to identify groups, we identify members belonging to Sagittarius (Sgr) Streams, Monoceros Ring, Virgo Overdensity, Hercules–Aquila Cloud, Orphan Streams, and other unknown substructures and find that the Sgr streams account for a large part of grouped stars beyond 20 kpc and enhance the increase of substructure with distance and metallicity. For the first time, we identify spectroscopic members of Monoceros Ring in the southern and northern Galactic hemispheres, which presents a rotation of about 185 km s?1 and a mean metallicity of ?0.66 dex. |
| 语种 | 英语 |
| WOS记录号 | IOP:0004-637X-880-1-ab2462 |
| 出版者 | The American Astronomical Society |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/28775]  |
| 专题 | 中国科学院国家天文台 |
| 作者单位 | 1.SHAO, Chinese Academy of Sciences, Nandan Road, Shanghai 200030, People’s Republic of China 2.Physics and Space Science College, China West Normal University, 1 ShiDa Road, Nanchong 637002, People’s Republic of China 3.School of Astronomy and Space Science, University of Chinese Academy of Sciences, 19A Yuquan Road, Shijingshan District, Beijing 100049, People’s Republic of China 4.National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100101, People’s Republic of China xuexx@nao.cas.cn, ycq@bao.ac.cn |
| 推荐引用方式 GB/T 7714 | Yang,Chengqun,Xue,Xiang-Xiang,Li,Jing,等. Identifying Galactic Halo Substructure in 6D Phase Space Using ～13,000 LAMOST K Giants[J]. The Astrophysical Journal,2019,880(1). |
| APA | Yang,Chengqun.,Xue,Xiang-Xiang.,Li,Jing.,Zhang,Lan.,Liu,Chao.,...&Li,Chengdong.(2019).Identifying Galactic Halo Substructure in 6D Phase Space Using ～13,000 LAMOST K Giants.The Astrophysical Journal,880(1). |
| MLA | Yang,Chengqun,et al."Identifying Galactic Halo Substructure in 6D Phase Space Using ～13,000 LAMOST K Giants".The Astrophysical Journal 880.1(2019). |
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来源：国家天文台
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