That was quick. Last week researchers reported they had traced a cosmic blast of radio waves back to its source for the first time – but now another team of fast-acting astronomers has called the result into question.
These fast radio bursts (FRB) puzzle astronomers because their brevity makes them hard to trace to a source. On 25 February, a team lead by Evan Keane at the Jodrell Bank Observatory in the UK published a paper in the journal Nature claiming they had finally found the source of one of these mysterious signals.
They did this by following up an observation of a fast radio burst (FRB) and seeing a galaxy with a radio “afterglow” in the same direction. The discovery suggested that the blast was caused by two colliding neutron stars.
But now Peter Williams of the Harvard-Smithsonian Center for Astrophysics and his colleagues say that conclusion is wrong. After reading the paper and having doubts, they quickly got permission to use the Very Large Array radio telescope in Socorro, New Mexico, over the weekend to take another look at the galaxy – and it is glowing again. This shouldn’t happen if the FRB was the result of a cosmic collision. “That’s just not consistent with the model they lay out,” he says.
The galaxy probably contains what is known as an active galactic nucleus – a central region that glows brightly and variably in a number of wavelengths, including radio. These are common and should be an obvious explanation to rule out.
It is not clear why Keane’s team didn’t address this in their paper, he says. “Frankly, I don’t know how the referees let this happen. The authors at least have to explain why their interpretation is more probable.”
“It’s quite possible that identification is questionable,” says Jason Hessels of the Netherlands Institute for Radio Astronomy, who was not involved in either study. He thinks Williams’ active galactic nucleus explanation could be right. “In which case it is certainly not associated with the fast radio burst itself.”
New Scientist contacted Keane for comment but has not yet received a response.
Journal reference: arxiv.org/abs/1602.08434