Detection of several Fast Radio Bursts per month predicted

Fast Radio Bursts (FRBs) are bursts of radiation observed at radio frequencies that last only a few milliseconds. The physical mechanisms for generating FRBs are unclear, but there are a lot of intriguing suggestions. What is clear is that these are very energetic events, and their short durations suggest these are the hallmark of extreme events in the Universe; collapses, explosions, collisions involving compact objects.

The frequency-dependence of the pulse arrival time suggests that FRBs are extragalactic, prompting a flurry of theoretical discussion about the potential sources of these highly-energetic events. After the discovery of four FRBs with the Parkes radio telescope by an international team (including CAASTRO members Matthew Bailes, Ramesh Bhat, Andrew Jameson, Michael Kramer, and Willem van Straten), Curtin University’s Cath Trott, Steven Tingay and Randall Wayth published a Letter predicting the rate of FRB detections expected for the new Murchison Widefield Array radio telescope (MWA). The MWA’s low radio frequencies and large number of small antennas allows it to monitor a huge fraction of the sky all the time. This is where its main advantage lies, and it is likely to be an excellent instrument to survey the Universe for FRBs, with the expectation of several events per month. Crucially, because it is an array of antennas (and not a single dish), it has the ability to localise any detections on the sky. This will allow it to make the key link between the burst of radiation, and a particular galaxy in the Universe, providing information about its origin. This attribute is not possible with a single dish such as Parkes, which sees many galaxies at any one time.

Success of the MWA in its first few months of observing to discover these bursts will provide the first census of this new and exciting population. Conversely, failure of the MWA to detect the expected number will place strong constraints on the underlying source population, informing our knowledge of the progenitors of these energetic events.

by C. Trott

Publication details:

C. M. Trott, S. J. Tingay, R. B. Wayth in ApJ Letters 776 (2013): “Prospects for the Detection of Fast Radio Bursts with the Murchison Widefield Array