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Abstract |
The latest results from the LIGO-Virgo collaboration challenge the astrophysical
scenarios of black hole formation. In this talk, I will discuss the main
astrophysical formation channels of binary black holes. On the one hand,
models of stellar evolution and pair instability supernovae suggest a gap in the
mass spectrum of black holes between ~60 and ~120 Msun. The boundaries of
this gap depend on stellar rotation and on the efficiency of envelope removal.
On the other hand, extreme dynamical processes in dense star clusters can fill
the mass gap, via multiple stellar collisions, dynamical exchanges and
hierarchical mergers. Based on a data-driven model, I will discuss the merger
history of dynamical versus isolated binary compact objects across cosmic time,
and its dependence on the cosmic star formation rate and the stellar metallicity. |
