The stochastic background of gravitational waves from neutron star formation at cosmological distances

We investigate the stochastic gravitational wave background that results fr om neutron star birth throughout the Universe. The neutron star birth rate, as a function of redshift, is calculated using an observation-based model for the evolving star formation rate, together with an estimate of the rate of core-collapse supernovae in the nearby Universe and an estimate of the neutron star/black hole branching ratio. Using three sample waveforms, base d on numerical models of stellar core collapse by Zwerger & Muller, the spe ctral flux density, spectral strain, spectral energy density and duty cycle of the background have been computed. Our results show, contrary to recent claims, that the spectrum of the stochastic background clearly reflects th e different physics in the core-collapse models. For a star formation model that is corrected for dust extinction, the neutron star formation rate thr oughout the Universe is high enough to result in a nearly continuous backgr ound of gravitational waves, with spectral features that can be related to emission mechanisms.