Date:
Tue, 30/04/201312:30-13:30
Title: Collisional Supernovae
Abstract:
Stars which are tightly bound to a supermassive black hole at a galactic center occasionally collide with one another. Due to the very high (“hyper”) velocities involved, a large fraction of these collisions generates an explosive disruption of the two stars. We show that (1) the rate of such collisions settles on a steady state with the capture rate, and (2) the typical explosive flare brightens for several days, with a peak luminosity that is comparable to the lower-luminosity end of known supernovae. The explosion light curve is followed by another flare due to the accretion of ejected matter onto the black hole. Dedicated searches in the near universe could observe several such "collisional-supernovae'' per year.
Abstract:
Stars which are tightly bound to a supermassive black hole at a galactic center occasionally collide with one another. Due to the very high (“hyper”) velocities involved, a large fraction of these collisions generates an explosive disruption of the two stars. We show that (1) the rate of such collisions settles on a steady state with the capture rate, and (2) the typical explosive flare brightens for several days, with a peak luminosity that is comparable to the lower-luminosity end of known supernovae. The explosion light curve is followed by another flare due to the accretion of ejected matter onto the black hole. Dedicated searches in the near universe could observe several such "collisional-supernovae'' per year.