Discovery of Two New Hypervelocity Stars from the LAMOST Spectroscopic Surveys

被引：29

作者：

Huang, Y. ^{[1
,2
]}

Liu, X. -W. ^{[1
,2
,3
]}

Zhang, H. -W. ^{[2
,3
]}

Chen, B. -Q. ^{[1
]}

Xiang, M. -S. ^{[4
]}

Wang, C. ^{[2
]}

Yuan, H. -B. ^{[5
]}

Tian, Z. -J. ^{[2
]}

Li, Y. -B. ^{[4
]}

Wang, B. ^{[6
]}

机构：

[1] Yunnan Univ, South Western Inst Astron Res, Kunming 650500, Yunnan, Peoples R China

[2] Peking Univ, Dept Astron, Beijing 100871, Peoples R China

[3] Peking Univ, Kavli Inst Astron & Astrophys, Beijing 100871, Peoples R China

[4] Chinese Acad Sci, Natl Astron Observ, Key Lab Opt Astron, Beijing 100012, Peoples R China

[5] Beijing Normal Univ, Dept Astron, Beijing 100875, Peoples R China

[6] Chinese Acad Sci, Yunnan Observ, Key Lab Struct & Evolut Celestial Objects, Kunming 650216, Yunnan, Peoples R China

来源：

ASTROPHYSICAL JOURNAL LETTERS | 2017年 / 847卷 / 01期

基金：

中国国家自然科学基金; 中国博士后科学基金;

关键词：

Galaxy: center; Galaxy: halo; Galaxy: kinematics and dynamics; stars: early-type; GALACTIC HALO; BLACK-HOLE; ORIGIN; MASS; EJECTION; MILKY;

D O I：

10.3847/2041-8213/aa894b

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We report the discovery of two new unbound hypervelocity stars (HVSs) from the LAMOST spectroscopic surveys. They are, respectively, a B2V-type star of similar to 7M(circle dot) with a Galactic rest-frame radial velocity of 502 km s(-1) at a Galactocentric radius of similar to 21 kpc and a B7V-type star of similar to 4M(circle dot) with a Galactic rest-frame radial velocity of 408 km s-1 at a Galactocentric radius of similar to 30 kpc. The origins of the two HVSs are not clear given their currently poorly measured proper motions. However, the future data releases of Gaia should provide proper motion measurements accurate enough to solve this problem. The ongoing LAMOST spectroscopic surveys are expected to yield more HVSs to form a statistical sample, providing vital constraints on understanding the nature of HVSs and their ejection mechanisms.

引用

页数：5

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