Black holes, neutron stars, and gravitational waves*

Recently, LIGO and VIRGO have detected the first gravitational waves from binary black hole mergers, and one binary neutron star merger. This latter event, GW170817, was particularly exciting because it was also observed in the electromagnetic spectrum, from gamma-rays to the radio, making it truly a multi-messenger event. The detections of binary mergers provide a new way to study compact objects--black holes and neutron stars--in the universe. I will discuss some of the scientific questions that gravitational waves will help us address, such as testing general relativity, studying matter inside neutron stars, learning how large black holes can form, and finding the origin of heavy elements in the universe. I will also discuss computational models of merging binaries that help us interpret the gravitational wave data, and introduce Dendro-GR, the new computer code we are using to study intermediate-mass black holes.