2004/04/30 by Motohiro Enoki, Kaiki Taro Inoue, Kaiki T. Inoue +3 · 140 citations
Physics and Astronomy · #Amplitude #Astronomy #Astrophysics #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy merger #Gravitational wave #Optics #Physics #Pulsars and Gravitational Waves Research #Quasar #Radio Astronomy Observations and Technology #Redshift #Supermassive black hole #astro-ph #gr-qc
paper · pdf · doi:10.1086/424475
published in The Astrophysical Journal 615(1), 19-28 (IOP Publishing) · Accepted for publication in ApJ. 11 pages, 7 figures
arxiv created 2004/07/15 · openalex publication_date 2004/11/01 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
We investigate the expected gravitational wave emission from coalescing supermassive black hole (SMBH) binaries resulting from mergers of their host galaxies. When galaxies merge, the SMBHs in the host galaxies sink to the center of the new merged galaxy and form a binary system. We employ a semianalytic model of galaxy and quasar formation based on the hierarchical clustering scenario to estimate the amplitude of the expected stochastic gravitational wave background due to inspiraling SMBH binaries and bursts due to the SMBH binary coalescence events. We find that the characteristic strain amplitude of the background radiation is h c ( f ) ~ 10 -16 ( f /1 μHz) -2/3 for f ≲ 1 μHz just below the detection limit from measurements of the pulsar timing provided that SMBHs coalesce simultaneously when host galaxies merge. The main contribution to the total strain amplitude of the background radiation comes from SMBH coalescence events at 0 < z < 1. We also find that a future space-based gravitational wave interferometer such as the planned Laser Interferometer Space Antenna might detect intense gravitational wave bursts associated with coalescence of SMBH binaries with total mass M tot < 10 7 M ☉ at z ≳ 2 at a rate ~1.0 yr -1 . Our model predicts that burst signals with a larger amplitude h burst ~ 10 -15 correspond to coalescence events of massive SMBH binary with total mass M tot ~ 10 8 M ☉ at low redshift ( z ≲ 1) at a rate ~0.1 yr -1 , whereas those with a smaller amplitude ( h burst ~ 10 -17 ) correspond to coalescence events of less massive SMBH binaries with total mass M tot ~ 10 6 M ☉ at high redshift ( z ≳ 3).