Abstract
The enormous velocities of the so-called hypervelocity stars (HVSs) derive, likely, from close interactions with massive black holes, binary stars encounters or supernova explosions. In this paper, we investigate the origin of HVSs as consequence of the close interaction between the Milky Way central massive black hole and a passing-by young stellar cluster. We found that both single and binary HVSs may be generated in a burst-like event, as the cluster passes near the orbital pericentre. High-velocity stars will move close to the initial cluster orbital plane and in the direction of the cluster orbital motion at the pericentre. The binary fraction of these HVS jets depends on the primordial binary fraction in the young cluster. The level of initial mass segregation determines the value of the average mass of the ejected stars. Some binary stars will merge, continuing their travel across and out of the Galaxy as blue stragglers.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 451-460 |
| Number of pages | 10 |
| Journal | Monthly Notices of the Royal Astronomical Society |
| Volume | 467 |
| Issue number | 1 |
| DOIs | |
| State | Published - May 2017 |
Funding
Part of this work was performed at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1066293. At this regard, RCD thanks the Simons Foundation for the grant that allowed him a period of stay at the Aspen Center for Physics where he developed part of this work. GF acknowledges hospitality from Sambaran Banerjee and Pavel Kroupa, and the University of Bonn, where the early plan for this work was conceived. GF acknowledges Sverre Aarseth for fruitful discussions on the use of the code NBODY6. GF acknowledges Andreas K?pper and Yohai Meiron for useful and helpful discussions and comments about the contents investigated in this paper. Part of this work was performed at the Aspen Center for Physics, which is supported by National Science Foundation grant PHY-1066293. At this regard, RCD thanks the Simons Foundation for the grant that allowed him a period of stay at the Aspen Center for Physics where he developed part of this work.
Keywords
- Galaxies: star clusters: general
- Galaxy: centre
- Galaxy: kinematics and dynamics
- Stars: kinematics and dynamics
ASJC Scopus subject areas
- Astronomy and Astrophysics
- Space and Planetary Science