A Stochastic GW Background from Massive Black Hole Binaries
Abstract: I will present our models of MBH Binary (MBHB) evolution using the population of black holes and galaxies from the Illustris simulations. Environmental hardening processes like dynamical friction and stellar scattering are required for most binaries to coalesce within a Hubble time. These environmental effects reveal characteristic signatures on the resulting stochastic, Gravitational Wave Background (GWB). Our recent results show the effects of both environment and eccentric evolution on the GWB spectral shape and the time until Pulsar Timing Arrays (PTA) will detect it. In particular, our models suggest that the International PTA will make a detection within 12-14 years.