Using Pulsar Timing observations to understand the formation and evolution of supermassive black hole binaries

The astrophysical processes that form and harden supermassive black hole binaries impart distinct features that may be observed in the gravitational-wave spectrum within the sensitive frequency range of Pulsar Timing Arrays (PTA). We investigate how well the various formation and hardening mechanisms can be constrained by applying Bayesian inference to simulated PTA data sets. We find that even without strong priors on the merger rate, any detection of the signal will place interesting constraints on the astrophysical models. Folding in priors on the merger rate allows us to place interesting constraints on the astrophysical models even before a detection is made.