Speeding up of Binary Merger Due to "Apparent" Gravitational Wave Emissions

TL;DR

This paper investigates how the presence of a nearby massive object, like an intermediate or supermassive black hole, accelerates the merger of binary black holes by affecting gravitational wave emissions.

Contribution

It introduces a scenario where a nearby massive object speeds up binary black hole mergers, a process previously thought to be very slow.

Findings

Merging timescales are significantly reduced with a nearby massive object.

Supermassive black holes lead to higher merger rates than intermediate mass black holes.

The presence of a third massive object alters gravitational wave emission dynamics.

Abstract

Gravitational waves from binary black hole pairs have emerged as an important observational tool in current times. The energy of the BH - BH binary pair is radiated in the form of gravitational waves and to compensate for that energy, kinetic energy of the system decreases gradually. Consequently the mutual separation of the objects decreases with time and tends to merge. The whole process may require a very long time comparable or longer than the age of the universe, specially in the case of low mass mergers. We have examined the case in which a massive object compared to the individual masses comprising the binary pair is present nearby such a system. We have found that in this case the merging process takes place much rapidly than that of the conventional BH-BH merging process. Scenarios with both an Intermediate Mass Black Hole (IBMH) ($10^{5}\:M_{\odot}$) as well as a Super Massive Black Hole (SMBH) have been studied and the latter has been found to provide a much higher overall rate for the BH-BH merger process.