90 likes | 191 Views
The Current Status of Hypervelocity Stars. Galactic Center Workshop Shanghai 2009 Oct 21 Warren R. Brown Smithsonian – CfA Collaborators: Margaret Geller, Scott Kenyon. The First Hypervelocity Star. +850 km/s (!!). Links to the Black Hole Ejection Mechanism Observed Properties.
E N D
The Current Status ofHypervelocity Stars Galactic Center Workshop Shanghai 2009 Oct 21 Warren R. Brown Smithsonian – CfA Collaborators: Margaret Geller, Scott Kenyon
The First Hypervelocity Star +850 km/s (!!)
Links to the Black HoleEjection MechanismObserved Properties • Velocity distribution • Spatial distribution • Temporal distribution • Stellar Rotation distribution Single MBH + binary star (Hills 1988) Binary MBH + single star (Yu & Tremaine 2003) Stellar BH + MBH + star (O’Leary & Loeb 2008) (Sesana et al 2007) (Levin 2006) Hansen (2007) Lockmann & Baumgardt (2008) Lopez-Morales & Bonanos (2008)
Latest Results HVSs Brown et al (2009a)
Links to Dark Matter Brown et al. (2009b)
HVS = Galactic Center origin • There are unbound stars in halo. • MBH in the GC. • Stars orbit the MBH. • HVSs are B stars. • GC full of B stars. • Travel times < lifetimes. • Nobs = Npredicted. Heber et al (2008) but . . .
Runaway B Stars Runaways HVSs • Binary disruption: • Supernova • Dynamical Bromley, Kenyon, Brown & Geller (2009)
Runaway vs. HVS Bromley, Kenyon, Brown & Geller (2009) Brown et al. (2009b)
Conclusions 1. = 2. NY Times