Exploring the multiband gravitational wave background with a semi-analytic galaxy formation model

Abstract

An enormous number of compact binary systems, spanning from stellar to supermassive levels, emit substantial gravitational waves during their final evolutionary stages, thereby creating a stochastic gravitational wave background (SGWB). We calculate the merger rates of stellar compact binaries and massive black hole binaries using a semi-analytic galaxy formation model -- Galaxy Assembly with Binary Evolution (GABE) in a unified and self-consistent approach, followed by an estimation of the multi-band SGWB contributed by those systems. We find that the amplitudes of the principal peaks of the SGWB energy density are within one order of magnitude ${\Omega }_{GW}\sim 10^{-9}-10^{-8}$. This SGWB could easily be detected by the Square Kilometre Array (SKA), as well as planned interferometric detectors, such as the Einstein Telescope (ET) and the Laser Interferometer Space Antenna (LISA). The energy density of this background varies as ${\Omega }_{GW}\propto f^{2/3}$ in SKA band. The shape of the SGWB spectrum in the frequency range $\sim [10^{-4}$,$1]$Hz could allow the LISA to distinguish the black hole seed models. The amplitude of the SGWB from merging stellar binary black holes (BBHs) at $\sim 100$ Hz is approximately 10 and 100 times greater than those from merging binary neutron stars (BNSs) and neutron-star-black-hole (NSBH) mergers, respectively. Note that, since the cosmic star formation rate density predicted by GABE is somewhat lower than observational results by $\sim 0.2$ dex at z < $\sim 2$, the amplitude of the SGWB in the frequency range $\sim [1$, $10^4]$ Hz may be underestimated by a similar factor at most.

12 pages, 5 figures

References in corpus (14)

• The NANOGrav 15-year Data Set: Evidence for a Gravitational-Wave Background
• GW190521: A Binary Black Hole Merger with a Total Mass of $150M_{\odot }$
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• Search for an isotropic gravitational-wave background with the Parkes Pulsar Timing Array
• Searching for the nano-Hertz stochastic gravitational wave background with the Chinese Pulsar Timing Array Data Release I
• Formation of Supermassive Black Holes by Direct Collapse in Pregalactic Halos
• Supermassive black hole formation during the assembly of pre-galactic discs
• Probing non-tensorial polarizations of stochastic gravitational-wave backgrounds with ground-based laser interferometers
• Evolution of the Luminosity Function, Star Formation Rate, Morphology and Size of Star-forming Galaxies Selected at Rest-frame 1500A and 2800A
• Exploring the Lower Mass Gap and Unequal Mass Regime in Compact Binary Evolution
• Stochastic Gravitational Wave Background from Neutron Star r-mode Instability Revisited
• Accretion-modified stellar-mass black hole distribution and milli-Hz gravitational wave backgrounds from galaxy centre
• An estimate of the stochastic gravitational wave background from the MassiveBlackII simulation
• The optimal approach of detecting stochastic gravitational wave from string cosmology using multiple detectors

Cited by in corpus (3)

• Implications for the Supermassive Black Hole Binaries from the NANOGrav 15-year Data Set
• Forecast Analysis of Astrophysical Stochastic Gravitational Wave Background beyond general relativity: A Case Study on Brans-Dicke Gravity
• Exploring the anisotropic gravitational wave background from all-sky mock gravitational wave event catalogues