What does LIGO event GW150914 teach us about stellar dynamics?

Abstract: The detection of GW150914 by the Laster Interferometer Gravitational-wave Observatory (LIGO) opens a new episode in astronomy in which we can use Einstein’s ripples in spacetime  to probe astronomical objects and investigate their distribution and evolution. In this talk, I will briefly review the properties of GW150914, namely the nature of its components (black holes), the components’ masses, spin parameters, and orbital eccentricity. Then I will discuss in depth that these properties bear imprints of a series of stellar dynamical processes, through which black hole binaries (BHBs) are assembled. In particular, I will point out a universal correlation for LIGO BHBs-between large black hole mass, low spin, and low orbital eccentricity-that is derived from the current understanding of stellar dynamics. This prediction, in fact made earlier than the detection of GW150914, is now proven to be true. This success not only demonstrates the power of stellar dynamics, but also provides new guidelines for people modeling waveforms and searching for gravitational-wave signals in the LIGO data stream.

•  Dr. Chen’s main research interest is galactic dynamics, with a focus on astrophysical systems containing gravitational-wave sources.