Gravitational Wave and X-ray Signals from Stellar Disruption by a Massive Black Hole

Gravitational waves and X-ray flares are expected from tidal disruption of stars by a massive black hole. Using a relativistic smoothed particle hydrodynamics code, we investigate the fate of main sequence and Helium stars in plunge orbits passing near Schwarzschild or a Kerr black holes of mass ∼ 10M⊙. We show that quadrupole gravitational waves emitted during the tidal disruption process are described reasonable well by a point particle approximation even in the strong encounter case. X-ray flares (∼ 1keV for the disruption of solar-type stars by ∼ 106M⊙ black holes) will be associated with the gravitational wave signal. The hardness of the X-ray flare may serve as a diagnostic of the mass of the black hole involved in the tidal disruption process. Subject headings: gravitational waves – x-rays: bursts– black hole physics – galaxies: nuclei – hydrodynamics