Gravitational wave background from Population III black hole formation

Abstract

We study the generation of a stochastic gravitational wave (GW) background produced from a population of core-collapse supernovae, which form black holes in scenarios of structure formation. We obtain, for example, that the formation of a population (Population III) of black holes, in cold dark matter scenarios, could generate a stochastic GW background with a maximum amplitude of hBG ≃ 10-24 and corresponding closure energy density of ΩGW ∼ 10-7, in the frequency band υobs ≃ 30-470 Hz (assuming a maximum efficiency of generation of GWs, namely, εGwmax = 7 × 10-4) for stars forming at redshifts z ≃ 30-10. We show that it will be possible in the future to detect this isotropic GW background by correlating the signals of a pair of 'advanced' LIGO observatories (LIGO III) at a signal-to-noise ratio of ≃40. We discuss what astrophysical information could be obtained from a positive (or even a negative) detection of such a GW background generated in scenarios such as those studied here. One of them is the possibility of obtaining the initial and final redshifts of the emission period from the observed spectrum of GWs.