Rotating Halo Traced by the K-giant Stars from LAMOST and Gaia
文献类型:期刊论文
作者 | Tian,Hao; Liu,Chao![]() ![]() |
刊名 | The Astrophysical Journal
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出版日期 | 2019-01-30 |
卷号 | 871期号:2 |
关键词 | galaxies: individual (Milky Way) Galaxy: halo Galaxy: kinematics and dynamics |
ISSN号 | 0004-637X |
DOI | 10.3847/1538-4357/aaf6e8 |
英文摘要 | Abstract With the help of Gaia DR2, we are able to obtain the full 6D phase space information for stars from the Large Sky Area Multi-Object Fibre Spectroscopic Telescope DR5. With high precision of the position, velocity, and metallicity, the rotation of the local stellar halo is presented using the K-giant stars with [Fe/H]??1 dex within 4 kpc from the Sun. By fitting the rotational velocity distribution with the three-Gaussian components, stellar halo, disk, and counterrotating hot population, we find that the local halo progradely rotates with km s?1, providing the local standard of the rest velocity of VLSR?=?232 km s?1. Meanwhile, we obtain the dispersion of rotational velocity is km s?1. Although the rotational velocity strongly depends on the choice of VLSR, the trend of prograde rotation is substantial even when VLSR is set at as low as 220 km s?1. Moreover, we derive the rotation for subsamples with different metallicities and find that the rotational velocity is essentially not correlated with [Fe/H]. This may hint at a secular evolution origin of the prograde rotation. It shows that the metallicity of the progradely rotating halo is peaked within ?1.9?[Fe/H]??1.6 without considering the selection effect. We also find a small fraction of counterrotating stars with larger dispersion and a lower metallicity. Finally, the disk component rotates with km s?1 and km s?1, which is quite consistent with the metal-weak thick disk population. |
语种 | 英语 |
WOS记录号 | IOP:0004-637X-871-2-AAF6E8 |
出版者 | The American Astronomical Society |
源URL | [http://ir.bao.ac.cn/handle/114a11/24984] ![]() |
专题 | 中国科学院国家天文台 |
作者单位 | Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, Datun Road 20A, Beijing 100012, People’s Republic of China; liuchao@nao.cas.cn |
推荐引用方式 GB/T 7714 | Tian,Hao,Liu,Chao,Xu,Yan,et al. Rotating Halo Traced by the K-giant Stars from LAMOST and Gaia[J]. The Astrophysical Journal,2019,871(2). |
APA | Tian,Hao,Liu,Chao,Xu,Yan,&Xue,Xiangxiang.(2019).Rotating Halo Traced by the K-giant Stars from LAMOST and Gaia.The Astrophysical Journal,871(2). |
MLA | Tian,Hao,et al."Rotating Halo Traced by the K-giant Stars from LAMOST and Gaia".The Astrophysical Journal 871.2(2019). |
入库方式: OAI收割
来源:国家天文台
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