Tuesday, January 26, 2016
Gravitational-Wave Research Seminar
Population Explosion: Understanding the Populations of Hot Jupiters, Black Holes, Earth-like Exoplanets, and (Eventually) LIGO Sources
Will Farr, University of Birmingham
It is an exciting time for gravitational wave astronomy. The Advanced LIGO detectors have just finished their first observing run after several years of upgrades. As we move forward into the advanced detector era, much of the astrophysics we hope to extract from the anticipated detections will come from studies of *populations* of compact binary coalescences rather than individual events. This situation is hardly unique in astronomy. In this talk, I will discuss the astrostatistical techniques that I and others have developed to analyse astronomical populations that are subject to observational selection effects, uncertain measurements, and contamination from non-population signals. I will cover examples from populations of hot Jupiters, where this type of analysis can constrain the various proposed formation scenarios for these objects; populations of black-hole X-Ray binaries, where this type of analysis indicates a likely "mass gap" between the lightest black holes and the heaviest neutron stars, possibly constraining the supernova processes that form these objects; populations of exoplanets, where this type of analysis allows us to measure the frequency of Earth-like planets in Earth-like orbits about their Sun-like stars, a crucial parameter informing future exoplanet surveys and a first step to answering the question, "How unique is life on Earth?" I will discuss the application of these techniques in the context of the future of Advanced LIGO, where we eventually hope to collect a population of compact binary inspiral signals. Population analysis of these signals can reveal information about the end-stages of massive binary stellar evolution, the mechanisms underlying supernova explosions, dynamical conditions in dense stellar environments, and possibly tests of strong-field gravity.