Kavli Affiliate: Pau Amaro Seoane
| First 5 Authors: Fupeng Zhang, Pau Amaro Seoane, , ,
| Summary:
We recently developed a Monte-Carlo method (GNC) that can simulate the
dynamical evolution of a nuclear stellar cluster (NSC) with a massive black
hole (MBH), where the two-body relaxations can be solved by the Fokker-Planck
equations in energy and angular momentum space. Here we make a major update of
GNC~ by integrating stellar potential and adiabatic invariant theory, so that
we can study the self-consistent dynamics of NSCs with increasing mass of the
MBH. We perform tests of the self-adaptation of cluster density due to MBH mass
growth and Plummer core collapse, both finding consistent results with previous
studies, the latter having a core collapse time of $sim 17t_{rm rh}$ by GNC,
where $t_{rm rh}$ is the time of half-mass relaxation. We use GNC~ to study
the cosmological evolution of the properties of NSC and the mass of MBH
assuming that the mass growth of the MBH is due to loss-cone accretion of stars
(e.g., tidal disruption of stars) and stellar black holes, and compare the
simulation results with the observations of NSCs in Milky-Way or near-by
galaxies. Such scenario is possible to produce MBHs with mass $10^5sim
10^7,M_odot$ for NSCs with stellar mass of $10^6sim 10^9,M_odot$. In
Milky-Way’s NSC, to grow MBH up to $4times 10^6,M_odot$, its size needs to
be $sim 1.7$ times more compact in early universe than the current value. MBHs
with current masses $>6times 10^{7},M_odot$ seem difficult to explain by
loss-cone accretion alone, and thus may require other additional accretion
channels, such as gas accretion.
| Search Query: ArXiv Query: search_query=au:”Pau Amaro Seoane”&id_list=&start=0&max_results=3