Brownian Motion of Black Holes in Dense Nuclei

摘要: We evaluate the Brownian motion of a massive particle ("black hole") at center galaxy using N-body simulations. Our models have power-law central density cusps like those observed centers elliptical galaxies. The simulations show that black hole achieves steady state kinetic energy is substantially different from what would be predicted based on properties model in absence hole. reason appears to responds stars whose velocities themselves been raised by presence Over wide range slopes and masses, hole's mean equal under assumption it equipartition with lying within distance ~rh/2 it, where rh influence radius. dependence velocity mass approximately V2 ∝ M, 0.5 γ 2.0, index stellar profile, ρ r-γ. This less steep than M which effect ignored. spectrum also evaluated found consistent predictions Chandrasekhar's theory. use these results derive probability function for Milky Way measurement its proper-motion velocity. Interesting constraints MBH will require resolution exceeding km s-1.