## [1104.2044] Gravitational wave background from coalescence of black hole binaries population

Authors: Stefania Marassi, Raffaella Schneider, Giovanni Corvino, Valeria Ferrari, Simon Portergies Zwart

Date: 11 Apr 2011

Abstract: We compute the stochastic gravitational wave background(GWB) generated by a cosmological population of (BH-BH) binaries. Using an updated version of the SeBa population synthesis code, we simulate a large sample of binary systems. Adopting a set of "standard" conservative assumptions calibrated to reproduce the observed properties of single Wolf-Rayet stars and double pulsars, we extract fundamental statistical information on (BH-BH) physical parameters (primary and secondary BH masses, orbital separations and eccentricities, formation and merger timescales). We then derive the binary birth rate from the cosmic star formation history obtained from a numerical study which reproduces the available observations at redshifts $z < 8$. Making a significant step forward to previous calculations, where only the inspiral signal was considered, we include the contribution to the GWB coming from the merging of the two BHs and from the ring-down of the final BH. We find that the GWB from the inspiral phase is characterized by a maximum amplitude in the range $\Omega_{\rm GW} \sim [0.88-1.7]\times 10ˆ{-7}$ at frequencies $[80 - 100]$ Hz; this signal could be detected with a (S/N)$> 100$ by a second generation interferometer, such as Advanced LIGO/VIRGO, with 1-3 years of integration. Third generation detectors, such as the Einstein Telescope, could easily detect the GWB generated by the emission during all the three phases of the evolution. The frequency dependence and amplitude of the GWB generated during the merger and ring-down is very sensitive to the adopted core mass threshold for BH formation. This opens up the possibility to better understand the final stages of the evolution of massive stellar binaries using observational constraints on the associated gravitational wave emission.

#### Apr 14, 2011

1104.2044 (/preprints)
2011-04-14, 21:35