Production of EMRIs in Supermassive Black Hole Binaries

Understand

We consider the formation of extreme mass-ratio inspirals (EMRIs) sourced from a stellar cusp centred on a primary supermassive black hole (SMBH) and perturbed by an inspiraling less massive secondary SMBH.

• The problem is approached numerically, assuming the stars are non-interacting over these short timescales and performing an ensemble of restricted three-body integrations.
• From these simulations we see that not only can EMRIs be produced during this process, but the dynamics are also quite rich.
• In particular, most of the EMRIs are produced through a process akin to the Kozai-Lidov mechanism, but with strong effects due to the non-Keplerian stellar potential, general relativity, and non-secular oscillations in the angular momentum on the orbital timescale of the binary SMBH system.