Physics Colloquium

At nanohertz frequencies, gravitational waves are expected to be produced by in-spiraling supermassive black hole binaries, as well as potentially more exotic sources such as cosmic strings or cosmological phase transitions.  The ensemble of supermassive black hole binaries should produce a gravitational wave background.  Following in the initial efforts of JPL researcher R. Hellings and G. Downs, for the past 15 years, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has been constructing and monitoring a pulsar timing array to detect and study these gravitational waves.  This detector uses some of the world's largest and most sensitive radio telescopes to measure precise arrival times from millisecond pulsars.  This talk presents the NANOGrav 15 Year Data Set, describing the data set itself, a comprehensive detector characterization effort, and the latest updates on the search for the gravitational wave background.

Live stream via YouTube: https://www.youtube.com/watch?v=b1GhSgC8wmw

Zoom link available to those w/valid Caltech ID. Contact [email protected] before 3pm on June 29 2023 for link. Email must come from .caltech.edu email address.

The colloquium is held in Hameetman Auditorium, Cahill Center for Astronomy and Astrophysics - In person is open to those with a valid Caltech ID.