Previous abstract Next abstract

Session 29 - Dynamical Evolution of Galaxies.
Oral session, Monday, January 13
Harbour C,

[29.03] Evolution of a Tidally Disrupted Star Around a Massive Black Hole

A. Ulmer (Princeton U. Obs.)

Stars in galactic nuclei can be tidally disrupted by a massive central black hole. The stellar debris experiences strong shocks which thermalize the orbital energy and result in a circular orbit. I investigate the evolution of this stellar debris from a narrow torus to an extended disk which accretes onto the black hole. From a diverse family of hydrostatic thick disks models, evolutionary time-sequences are formed. The range of physically allowed evolutionary tracks is determined by enforcing only global conservation laws and a requirement which stems from a non-negative viscosity. While there is no a priori way to discern which evolutionary track is actually followed, by studying the range of evolutionary tracks, the radiative efficiencies, luminosities, and time-scales can all be bracketed. For Schwarzschild black holes, the efficiency, E_radiated/M_accreatedc^2 ranges between about 0.06 and 0.005.

Program listing for Monday