Joint Astrophysics Colloquium

Fast Radio Bursts on the Horizon

Sarah Burke-Spolaor

California Institute of Technology

Reports of intense, frequency-swept radio pulses — lasting only milliseconds — have been fuelling a heated debate as to the origin of this emission. Until recently, it was widely hypothesized that such bursts were Earth-local, but a growing body of evidence is demonstrating that some may be arriving from extragalactic sources at redshifts up to z~2. As an extragalactic population, these bursts would be unprecedented probes of extragalactic baryons and hitherto unidentified physical processes. I will outline the state of radio burst research, and describe the emerging evidence that we are not just seeing one, but instead several, sub-populations that range from local to cosmic origins. I will discuss potential progenitors of extragalactic “Fast Radio Bursts”, and describe ongoing work in the race to identify where they are, and how they are.