Program: GS-2022B-Q-123

We propose to use a target of opportunity (ToO) program to study the nature and origin of fast radio bursts (FRBs). FRBs are bright millisecond-duration radio pulses originated at extragalactic distances. Their radio emission, however, offers limited insight into their physical nature, and especially, cannot be used to precisely establish the source redshift. We propose to use Gemini/GMOS to perform rapid ToO imaging and spectroscopic follow-up observations of real time well-localized (<1") FRB events, in order to characterize their host galaxies and any putative associated optical emission. The new advances in radio detectors are now delivering sub-arcsecond FRB localization (e.g. ASKAP, MeerKAT, VLA, EVN) and, together with the DWF program, this proposal would allow prompt and effective follow-up of FRBs. Our science goals range from establishing the energetics and progenitors of the FRBs from galaxy host demographics to leveraging these phenomena for cosmological constraints on the distribution of baryons within the intergalactic medium and circumgalactic medium.