MOCCA Survey Database I: Dissolution of tidally filling star clusters
  harbouring BH subsystems
  We investigate the dissolution process for dynamically evolving star clusters
embedded in an external tidal field by exploring the MOCCA Survey Database I,
with focus on the presence and evolution of a stellar-mass black hole
subsystem. We argue that the presence of a black hole subsystem can lead to the
dissolution of tidally filling star clusters and this can be regarded as a
third type of cluster dissolution mechanism (in addition to well-known
mechanisms connected with strong mass loss due to stellar evolution and mass
loss connected with the relaxation process). This third process is
characterized by abrupt cluster dissolution connected with the loss of
dynamical equilibrium. The abrupt dissolution is powered by strong energy
generation from a stellar-mass black hole subsystem accompanied by tidal
stripping. Additionally, we argue that such a mechanism should also work for
even tidally under-filling clusters with top-heavy initial mass function.
Observationally, star clusters which undergo dissolution powered by the third
mechanism would look as a 'dark cluster' i.e. composed of stellar mass black
holes surrounded by an expanding halo of luminous stars (Banerjee & Kroupa
2011), and they should be different from 'dark clusters' harbouring
intermediate mass black holes as discussed by Askar et al. (2017a). An
additional observational consequence of an operation of the third dissolution
mechanism should be a larger than expected abundance of free floating black
holes in the Galactic halo.
