Merging Black Holes in Dwarf Galaxies: Calculating Black Hole Coalescence Binary Timescales from Simulations for LISA Detection [GA]

http://arxiv.org/abs/2111.15035


Supermassive black holes (SMBHs) merging in dwarf galaxies will be detectable by the Laser Interferometer Space Antenna (LISA) in the mid-2030s. Previous cosmological hydrodynamic simulations have shown the prediction of massive black holes merging in dwarf galaxies, but these simulations are limited by their resolution and cannot follow black hole pairs all the way to coalescence. We calculate the delay time between black hole pairing and merger based on the properties of the black holes and their host galaxies, and use these properties to calculate gravitational wave strains for eleven different binary black holes that merge inside dwarf galaxies from eight cosmological simulations. This delay time calculation accounts for dynamical friction, loss-cone scattering and hardening of the binary due to gravitational radiation. Out of the eleven black hole mergers in the simulations, four black hole pairs will merge within a Hubble time and can be observed by LISA, one pair’s coalescence time is longer than the Hubble time, and the remaining six are unresolved due to resolution limitations of the simulation. As four out of five of the resolved close pairs merge within a Hubble time, we make the broad estimate that ~80% of close SMBH pairs in dwarf galaxies will merge and be detectable by LISA.

Read this paper on arXiv…

V. Cun, J. Bellovary and M. Katz
Wed, 1 Dec 21
109/110

Comments: 6 pages, 3 figures, to be submitted to MNRAS