Tidal disruption flares from stars on eccentric orbits
  We study tidal disruption and subsequent mass fallback for stars approaching
supermassive black holes on bound orbits, by performing three dimensional
Smoothed Particle Hydrodynamics simulations with a pseudo-Newtonian potential.
We find that the mass fallback rate decays with the expected -5/3 power of time
for parabolic orbits, albeit with a slight deviation due to the self-gravity of
the stellar debris. For eccentric orbits, however, there is a critical value of
the orbital eccentricity, significantly below which all of the stellar debris
is bound to the supermassive black hole. All the mass therefore falls back to
the supermassive black hole in a much shorter time than in the standard,
parabolic case. The resultant mass fallback rate considerably exceeds the
Eddington accretion rate and substantially differs from the -5/3 power of time.
