Astronomy Colloquium

Fast radio bursts (FRBs) are millisecond duration transient events of unknown physical origin that were discovered at GHz radio frequency in 2007 (the data was collected by the Parkes telescope in 2001). It is now well established that many of these bursts are located at a distance of several billion lightyears. And therefore the energy release in the radio band in these events is quite large. Using very general arguments, I will show that the radio emission is coherent, the magnetic field strength associated with the source of these events should be 10^{14}Gauss or more, and the electric field is of order 10^{10} esu. I will describe my recent work that magnetic field distortions (Alfven waves) are responsible for the strong electric field and the coherent radiation produced in these enigmatic events. I will also address polarization properties of the well known repeater. Reasons for believing that these transients are associated with young magnetars will also be described.