ABSTRACT

The LIGO and Virgo gravitational-wave observatories collected nearly a year of data with better sensitivity than ever before during the recent O3 observing run. Dozens of binary merger candidates were identified in near-real-time and shared with astronomers promptly, although no clear counterparts have been identified in this run. LIGO-Virgo collaboration members are currently re-analyzing the data to confirm and fully characterize most of those candidates and to search for other gravitational-wave signals in the data. Final analysis results are available for two events so far, with more on the way. The latest events studied are revealing new combinations of the masses in merging compact binary systems, including a binary neutron star merger with a total mass of about 3.4 solar masses (GW190425) and the first binary black hole merger confirmed to have distinctly different masses (GW190412). I will discuss these discoveries and what we have learned from them about the astrophysics of compact binary systems.

About the Speaker:

Peter Shawhan is a Professor in the University of Maryland Department of Physics, where he has been on the faculty since 2006. He is also a Fellow of the Joint Space-Science Institute. Shawhan received his Ph.D. from the University of Chicago and then spent 7 years at Caltech as a Postdoctoral Fellow and Staff Scientist before moving to Maryland. Shawhan has made gravitational wave detection his primary research focus since 1999 and has held numerous leadership positions within the LIGO Scientific Collaboration (LSC). He currently serves as Observational Science Coordinator for LIGO and is a member of the LSC Management Team.

Shawhan received the Richard A. Ferrell Distinguished Faculty Fellowship from the UMD Dept. of Physics in 2016, and received both the University System of Maryland Board of Regents' Faculty Award for Excellence in Scholarship, Research, or Creative Activity and the Kirwan Faculty Research and Scholarship Prize in 2018 for his contributions to LIGO's breakthrough discoveries of gravitational waves and the development of multi-messenger astronomy. He was elected a Fellow of the American Physical Society in 2019.