English

Gravitational Waves from Coalescing Black Hole MACHO Binaries

Astrophysics 2009-10-30 v1 General Relativity and Quantum Cosmology

Abstract

If MACHOs are black holes of mass about 0.5 solar mass, they must have been formed in the early universe when the temperature was about 1 GeV. We estimate that in this case in our galaxy's halo out to about 50kpc there exist about half billion black hole binaries whose coalescence times are comparable to the age of the universe, so that the coalescence rate will be about five hundredth events/year/galaxy. This suggests that we can expect a few events/year within 15Mpc. The gravitational waves from such coalescing black hole MACHOs can be detected by the first generation of interferometers in the LIGO/VIRGO/TAMA/GEO network. Therefore, the existence of black hole MACHOs can be tested within the next five years by gravitational waves.

Keywords

Cite

@article{arxiv.astro-ph/9708060,
  title  = {Gravitational Waves from Coalescing Black Hole MACHO Binaries},
  author = {Takashi Nakamura and Misao Sasaki and Takahiro Tanaka and Kip S. Thorne},
  journal= {arXiv preprint arXiv:astro-ph/9708060},
  year   = {2009}
}

Comments

6 pages, Latex, Accepted for publication in Apj. Letters

R2 v1 2026-07-22T09:35:01.826Z