|
The First Stars and Galaxies: Challenges for the Next Decade Participants
Contact: |
Talk
Title: Successive Merger of Multiple Massive Black Holes in a Primordial Galaxy Author(s): Ataru Tanikawa Abstract: Using highly-accurate N-body simulations, we investigate the evolution of multiple massive black holes (hereafter MBHs) in a primordial galaxy that is composed of dark matter and stars. The evolution is pursued as a fully collisional system, where not only three-body interaction of MBHs but also dynamical friction by dark matter and stars are incorporated. The MBHs initially have equal mass. As a result, it is found that five MBHs merge successively, emitting gravitational radiation, while the other five do not merge in several Gyr. We find that the key process for the successive merger of MBHs is angular momentum loss due to dynamical friction when they are in the off-central regions of the galaxy. Dynamical friction enhances three-body interactions of MBHs when they come into the central regions of the galaxy. The most massive MBH loses its angular momentum most effectively, so that a single highly massive BH forms in the galactic center. Our simulation results show that multiple MBHs can produce a heavier BH in the galactic center purely through N-body processes.
|