Title: Measuring the Spins of Binary Black Holes using Gravitational Waves
Abstract: Orbiting and colliding binary black holes are amongst the most extreme objects in the cosmos. Over the last eight years, the Laser Interferometer Gravitational-wave Observatory (LIGO) has detected over one hundred of these systems, from which we have learned a great deal about their individual and ensemble properties like mass and intrinsic angular momentum (spin). The spins of black holes in binaries are a unique and essential probe of fundamental physics on multiple scales, from internal stellar processes to the astrophysical environments in which compact binaries form and the evolution of the universe. Despite their astrophysical importance, spins for black holes remain poorly constrained with LIGO data, especially in contrast to other fundamental characteristics like mass. I will discuss the current status of spin measurements for both notable individual binary black hole systems and the astrophysical population as a whole, and ongoing challenges of making these measurements robust.
Refreshments begin at 3:30pm followed by the talk at 4:00pm