As powerful millisecond bursts of radio emission continue to light up our detectors from across the universe, the hunt for the origins of these fast radio bursts continues. It’s the search for light before and after the burst, however, that might prove key to unraveling their mystery.
An Extragalactic Puzzle
Artist’s impression of the ASKAP radio telescope finding a fast radio burst. Other observatories are shown joining in follow-up observations. [CSIRO/Andrew Howells]Since the first discovery of fast radio bursts (FRBs) more than a decade ago, we’ve found ~100 of them, including more than 20 that have been observed to repeat. Despite this growing sample — and though we’ve now localized repeating and non-repeating FRBs to distant host galaxies — we still don’t know with certainty what causes them.
Many of the leading origin theories for FRBs come with predictions of other emission that should complement the radio flash. The birth of a magnetized neutron star, for instance, should produce not only an FRB, but also a radio afterglow — steadier radio emission that appears after the burst and then slowly fades over time.
The fact that we haven’t yet found any radio afterglows definitively associated with FRBs means one ...