Dynamical evolution of stellar-mass black holes in dense stellar clusters: estimate for merger rate of binary black holes originating from globular clusters

Understand

We have performed N-body simulations of globular clusters (GCs) in order to estimate a detection rate of mergers of Binary stellar-mass Black Holes (BBHs) by means of gravitational wave (GW) observatories.

• For our estimate, we have only considered mergers of BBHs which escape from GCs (BBH escapers).
• BBH escapers merge more quickly than BBHs inside GCs because of their small semi-major axes.
• N-body simulation can not deal with a GC with the number of stars N ~ 10^6 due to its high calculation cost.