Physics Colloquium: Fast Radio Bursts: Enigmatic Flashes in the Sky

Fast radio bursts are dispersed millisecond flashes of radio waves originating from beyond the Milky Way. The origin of these flashes remains enigmatic, especially given that there are about ten thousand of these bursts every day at random spots in the sky. Our recent localization of a repeating FRB and the measurement of a redshift for its host galaxy has confirmed the cosmological origin and extraordinary energetics of FRBs. With observations over a broad spectral range, we have found intriguing new clues about the phenomenon: the burst polarization properties indicate an extreme magneto-ionic environment for the central engine, and dramatic structure in the burst dynamic spectra points to the role of propagation effects in the intergalactic and interstellar media.  Understanding the central engines of FRBs and unlocking their future use as cosmological probes will require a larger sample of FRBs, the discovery of other repeating sources, and the identification of more host galaxies, and progress is being made on all of these fronts.

Bio Sketch:

Shami Chatterjee is an astronomer working on gravitational waves, transient sources, and neutron stars. He is currently a Senior Research Associate at the Cornell Center for Astrophysics and Planetary Science and the Carl Sagan Institute. After a Ph.D. in Astronomy at Cornell University, Chatterjee was a Jansky Fellow at the National Radio Astronomy Observatory and the Harvard Smithsonian Center for Astrophysics, a University Fellow at the University of Sydney, and (briefly) an astronomer at the Australia Telescope National Facility. He is a member of the NANOGrav collaboration, building a Galactic-scale detector for low-frequency gravitational waves using pulsar timing. He also coordinates work on the repeating Fast Radio Burst 121102, co-chairs the Survey Science Group for the ongoing VLA Sky Survey, and struggles with an overabundance of teleconferences.