CRA Cosmic Coffee: Deborah Ferguson

Title: Gravitational Waves: Using Merger to Understand Ringdown

Abstract: With the advent of gravitational wave astronomy, we have newly found access to a wealth of knowledge in the form of gravitational waves. Scientists are working hard to extract as much information as possible from each of the ten binary black hole coalescences (and one binary neutron star coalescence) detected by LIGO and Virgo to date. From each stage of the coalescence, we can learn different details about the binary system. The gravitational waves emitted during ringdown contain information about the remnant black hole, namely the mass and spin. For the purposes of parameter estimation as well as for tests of general relativity, it is important to obtain a measurement of this spin. However, ringdown is difficult to detect so we discuss a method to determine the final spin using the instantaneous frequency of the gravitational wave during merger.