THE FINAL-PARSEC PROBLEM IN THE COLLISIONLESS LIMIT

摘要: A binary supermassive black hole loses energy via ejection of stars in a galactic nucleus, until emission gravitational waves becomes strong enough to induce rapid coalescence. Evolution the slingshot requires that be continuously supplied binary, and it is known spherical galaxies reservoir such quickly depleted, leading stalling at parsec-scale separations. Recent N-body simulations galaxy mergers isolated nonspherical suggest this may not occur less idealized systems. However, remains unclear what degree these conclusions are affected by collisional relaxation, which much stronger numerical than real galaxies. In study, we present novel Monte Carlo method can efficiently deal with both collisionless dynamics, models having arbitrary shapes. We show without final-parsec problem overcome only triaxial Axisymmetry enough, but even moderate departure from axisymmetry sufficient keep shrinking. find hardening rate always substantially lower maximum possible, "full-loss-cone" rate, decreases time, stellar-dynamical interactions nevertheless able drive coalescence on timescale <=1 Gyr any galaxy.