Speaker
Description
Traditional numerical simulations employing gravitational softening are unable to resolve the small-scale dynamics and gravitational wave emission from supermassive black hole binaries. Instead, the parsec-scale dynamics is typically modelled by post-processing the simulations using semi-analytic methods based on orbit-averaged equations. An alternative is to use a hybrid approach, such as the KETJU code, recently developed in our group. The KETJU code includes algorithmically regularised regions around every supermassive black hole (SMBH) and post-Newtonian terms in the equations of motion of the SMBHs. This approach allows for simultaneously following global galactic-scale dynamical and astrophysical processes while accurately solving the dynamics of SMBHs at sub-parsec scales and directly calculating the expected gravitational wave signal and the resulting recoil. Using the KETJU code, we study the evolution of recoiling SMBHs in both isolated merger and full cosmological simulations and provide predictions for their observability in ongoing large-scale photometric surveys such as Euclid.