• DOI:10.1088/0004-637X/723/1/812
• Corpus ID: 118860430

SEGUE-2 LIMITS ON METAL-RICH OLD-POPULATION HYPERVELOCITY STARS IN THE GALACTIC HALO

@article{Kollmeier2010SEGUE2LO,
  title={SEGUE-2 LIMITS ON METAL-RICH OLD-POPULATION HYPERVELOCITY STARS IN THE GALACTIC HALO},
  author={Juna A. Kollmeier and Andrew P. Gould and Constance M. Rockosi and Timothy C. Beers and Gillian R. Knapp and Jennifer A. Johnson and Heather L. Morrison and Paul Harding and Young Sun Lee and Benjamin Alan Weaver},
  journal={The Astrophysical Journal},
  year={2010},
  volume={723},
  pages={812 - 817}
}

• J. Kollmeier, A. Gould, +7 authors B. Weaver
• Published 13 August 2010
• Physics
• The Astrophysical Journal

We present new limits on the ejection of metal-rich old-population hypervelocity stars (HVSs) from the Galactic center (GC) as probed by the SEGUE-2 survey. Our limits are a factor of 3–10 more stringent than previously reported, depending on stellar type. Compared to the known population of B-star ejectees, there can be no more than 30 times more metal-rich old-population F/G stars ejected from the GC. Because B stars comprise a tiny fraction of a normal stellar population, this places significant limits on the combination of the GC mass function and the ejection mechanism for HVSs. In the presence of a normal GC mass function, our results require an ejection mechanism that is about 5.5 times more efficient at ejecting B stars compared to low-mass F/G stars.