Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center

Details Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center

2003-09-03

arxiv.org/abs/astro-ph/0309084v1

Astrophys.J.599:1129-1138,2003

Astronomy and Astrophysics

Astrophysics

23 pages, including 2 figures; accepted for publication in ApJ

Scientific paper

10.1086/379546

We study three processes that eject hypervelocity (>10^3 km/s) stars from the Galactic center: (i) close encounters of two single stars; (ii) tidal breakup of binary stars by the central black hole, as originally proposed by Hills; and (iii) three-body interactions between a star and a binary black hole (BBH). Mechanism (i) expels hypervelocity stars to the solar radius at a negligible rate, ~10^{-11}/yr. Mechanism (ii) expels hypervelocity stars at a rate ~ 10^{-5}(\eta/0.1)/yr, where \eta is the fraction of stars in binaries with semimajor axis a_b<~0.3 AU. For solar-mass stars, the corresponding number of hypervelocity stars within the solar radius R_0=8 kpc is ~60(\eta/0.1)(a_b/0.1 AU)^{1/2}. For mechanism (iii), Sgr A^* is assumed to be one component of a BBH. We constrain the allowed parameter space (semimajor axis, mass ratio) of the BBH. In the allowed region (for example, semimajor axis of 0.5x10^{-3} pc and mass ratio of 0.01), the rate of ejecting hypervelocity stars can be as large as ~10^{-4}/yr and the expected number of hypervelocity stars within the solar radius can be as large as ~10^3. Hypervelocity stars may be detectable by the next generation of large-scale optical surveys.

Affiliated with

Also associated with

No associations

Rating

Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ejection of hypervelocity stars by the (binary) black hole(s) in the Galactic center will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-301546