Black-Hole Spin Dependence in the Light Curves of Tidal Disruption Events. (arXiv:1207.6401v1 [astro-ph.CO])

Black-Hole Spin Dependence in the Light Curves of Tidal Disruption Events. (arXiv:1207.6401v1 [astro-ph.CO]):
A star orbiting a supermassive black hole can be tidally disrupted if the
black hole's gravitational tidal field exceeds the star's self gravity at
pericenter. Some of stellar tidal debris can become gravitationally bound to
the black hole and be subsequently accreted, leading to a bright
electromagnetic flare. In the Newtonian limit, this flare will have a light
curve that scales as t^-5/3 if the tidal debris has a flat distribution in
binding energy. We investigate the time dependence of the black-hole mass
accretion rate when tidal disruption occurs close enough the black hole that
relativistic effects are significant. We find that for orbits with pericenters
comparable to the radius of the marginally bound circular orbit, relativistic
effects can double the peak accretion rate and halve the time it takes to reach
this peak accretion rate. The accretion rate depends on both the magnitude of
the black-hole spin and its orientation with respect to the stellar orbit; for
orbits with a given pericenter radius in Boyer-Lindquist coordinates, a maximal
black-hole spin anti-aligned with the orbital angular momentum leads to the
largest peak accretion rate.

Note: LSST could detect multiple such events -- might provide limits, worth considering.