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Hypervelocity Stars II. The Bound Population

Warren R. Brown·Margaret J. Geller·Scott J. Kenyon·Michael J. Kurtz·Benjamin C. Bromley
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Abstract

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 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.

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Warren R. Brown, Margaret J. Geller, Scott J. Kenyon, Michael J. Kurtz, Benjamin C. Bromley. 2007-01-21. Hypervelocity Stars II. The Bound Population. https://doi.org/10.1086/513595

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