Symmetry of black hole ejections in mergers of galaxies

Abstract

The process of formation of four black hole systems in the center of a galaxy is simulated. Using an evolutionary model for the mergings of galaxies we determine the black hole masses and the merger times of their host galaxies. Mergers are presumed to lead to the formation of binary systems. Their evolution inside the host galaxy is followed until a collapse of the black hole binary happens or until a new merger with another galaxy occurs. In this way we include the possibility that the binaries collapse before a multiple black hole interaction is reached. When a four black hole system is formed, its evolution is calculated until black hole mergers or escapes occur. Ejection parameters such as the bending angle and the distance ratio in two-sided black hole ejections have been studied and compared with observations of two-sided radio sources. The simulations produce a good agreement with observations of double radio sources. The results also predict a so far unobserved class of radio sources which one should be able to nd in a careful study of extended radio sources which are not classical doubles.