Modeling Black-Hole/Neutron-Star Binaries with Rapid Black-Hole Spins

LIGO and Virgo have observed gravitational waves---ripples of curved spacetime---from binary black holes and from binary neutron stars. Looking forward, we hope to observe black hole-neutron star mergers, which (like binary neutron stars) are potential multi-messenger sources, emitting both electromagnetic and gravitational waves. Highly accurate models of these waves are important for helping to detect as many gravitational waves from merging black holes and neutron stars as possible while learning as much as possible about the waves' sources. I will discuss the progress of new simulations, using the Spectral Einstein Code, of black hole-neutron star mergers with rapidly rotating black holes, an astrophysically interesting but technically challenging case.