Hypervelocity Stars. II. The Bound Population
Hypervelocity Stars. II. The Bound Population
复制标题
超高速恒星。
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
B. Bromley
中科院分区：
文献类型：
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作者：
Warren R. Brown;M. Geller;S. Kenyon;Michael J. Kurtz;B. Bromley
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 σ) excess of B-type stars with large velocities +275 km s-1 < vrf < 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.
