Institute for Advanced Study / Princeton University Joint Astrophysics Colloquium

Fast radio bursts (FRBs) are a big puzzle in astrophysics. Observational evidence and theoretical arguments connect FRBs to magnetars, yet their emission mechanism is not established. One popular picture resembles pulsars on steroids, with radio luminosity enhanced by 10-14 orders of magnitude. This extrapolation is, however, in conflict with physical constraints. This talk will argue that FRBs are emitted by powerful ultrarelativistic explosions, which frequently occur in young hyper-active magnetars in distant galaxies. The explosion ejecta release radio waves into the ambient medium far from the magnetar, where the waves can escape. The mechanism of explosions and the origin of powerful radio waves will be discussed. A novel radiative mechanism will be presented and compared with observational data. Similar magnetic explosions may accompany mergers of neutron stars and black holes.