.. _physics-blackHoleBinaryMerger:

Black Hole Binaries Merger
==========================

Class providing models of black hole binary mergers---the outcome (final mass and spin) of the coalescence of two black holes of given masses and spins. When two galaxies merge their central black holes eventually form a bound binary and spiral together via dynamical friction, eventually merging through gravitational wave emission. The merger product mass and spin determine the subsequent evolution of the remnant black hole, including its subsequent accretion and feedback. Implementations are typically based on numerical relativity fitting formulae.

**Default implementation:** ``blackHoleBinaryMergerRezzolla2008``

Methods
-------

``merge`` → ``void``
   The properties of the black hole resulting from a binary merger.

   * ``double precision, intent(in ) :: massBlackHoleA , massBlackHoleB, spinBlackHoleA , spinBlackHoleB``

   * ``double precision, intent( out) :: massBlackHoleFinal , spinBlackHoleFinal``

.. _physics-blackHoleBinaryMergerRezzolla2008:

``blackHoleBinaryMergerRezzolla2008``
-------------------------------------

A black hole binary merger class that uses the fitting function of :cite:t:`rezzolla_final_2008` to compute the spin of the black hole resulting from a binary merger. The mass of the resulting black hole is assumed to equal the sum of the mass of the initial black holes (i.e. there is negligible energy loss through gravitational waves).

**(Default implementation)**