Interaction of Recoiling Supermassive Black Holes with Stars in Galactic Nuclei
报告人:
Prof. Fukun Liu
Astronomy Department, Peking University
报告时间:
2012-12-13 13:30
报告地点:
理科楼三楼报告厅
主办单位:
物理系
简介:
Supermassive black hole (SMBH) binaries (SMBHBs) are the products of galaxy mergers. The detections of the strong GW radiation and their possible electromagnetic counterparts are essential. The strong gravitational wave radiations emitting by compact and/or coalescing SMBHBs are the main targets of the Laser Interferometer Space Antenna (eLISA) and the ongoing gravitational wave detection program Pulsar Timing Array (PTA). Numerical relativity simulations suggest that the post-merger SMBH can gets a kick velocity up to 5000 km/s due to the anisotropic GW radiations. Here, we investigate the dynamical co-evolution and interaction of the recoiling SMBHs and their galactic stellar environments with one million direct N-body simulations including the stellar tidal disruption by the recoiling SMBHs. Our results show that the accretion of disrupted stars does not significantly affect the SMBH dynamical evolution. We investigate the stellar tidal disruption rates as a function of the dynamical evolution of oscillating SMBHs in the galactic nuclei. Our simulations show that most stellar tidal disruptions are contributed by the unbound stars and occur when the oscillating SMBHs pass through the galactic center. The averaged disruption rate is ~10^-6 M_sun yr^-1, which is about an order of magnitude lower than that by a stationary SMBH at similar galactic nuclei. Our results also show that a bound star cluster is around the oscillating SMBH of about ~0.7% the black hole mass. In addition, we discover a massive cloud of unbound stars following the oscillating SMBH. We also investigate the dependence of the results on the SMBH masses and density slopes of the galactic nuclei.
