Hypervelocity stars. II. The bound population

被引:69
作者
Brown, Warren R. [1 ]
Geller, Margaret J.
Kenyon, Scott J.
Kurtz, Michael J.
机构
[1] Smithsonian Astrophys Observ, Cambridge, MA 02138 USA
[2] Univ Utah, Dept Phys, Salt Lake City, UT 84112 USA
关键词
D O I
10.1086/513595
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
Hypervelocity stars (HVSs) are stars ejected completely out of the Milky Way by three-body interactions with the massive black hole in the Galactic center. We describe 643 new spectroscopic observations from our targeted survey for HVSs. We find a significant ( 3.5 sigma) excess of B-type stars with large velocities +275 km s(-1) < v(rf) < 450 km s(-1) and distances d > 10 kpc that are most plausibly explained as a new class of HVSs: stars ejected from the Galactic center on bound orbits. If a Galactic center ejection origin is correct, the distribution of HVSs on the sky should be anisotropic for a survey complete to a fixed limiting apparent magnitude. The unbound HVSs in our survey have a marginally anisotropic distribution on the sky, consistent with the Galactic center ejection picture.
引用
收藏
页码:311 / 318
页数:8
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