BLASTS of radio waves from space may deliver a much bigger wallop than expected. For the first time, we have seen one of these enigmatic fast radio bursts occurring together with a spurt of gamma rays, meaning their joint source may be a billion times more energetic than we thought.
FRBs have proved baffling since their discovery in 2007. Each torrent of radio waves lasts no more than a few milliseconds and we have only spotted 17 of them so far.
Finding accompanying signals at other wavelengths may be the key to decoding their source. But to observe such a paired event, we would have to be watching the same area of the sky with a radio telescope and a telescope operating at different wavelengths when an FRB occurs there.
“We’ve been really unlucky so far: we’re almost always looking in the wrong places to be helpful,” says Emily Petroffat the Netherlands Institute for Radio Astronomy.
But now we have a match. Derek Fox at Pennsylvania State University and his colleagues studied old data from the Burst Alert Telescope on NASA’s Swift spacecraft to see if any gamma-ray bursts coincided with FRBs. They found one example from 2013 (arxiv.org/abs/1611.03139).
That challenges lower-energy explanations for FRBs and points to their source being a more catastrophic event such as a supernova or neutron star merger. But it also increases the mystery in some ways, Fox says. “The whole suite of properties that we observed doesn’t really line up exactly with any of the predictions.”
Finding more bursts will help. “I’ve got my party hat ready,” says Petroff. “I think we’ll have the answer in the near future.”
This article appeared in print under the headline “Mystery radio bursts spew gamma rays too”