Webb Telescope Identifies Galaxy Behind Farthest Fast Radio Burst

Fast radio bursts are ultra-fast radio waves from deep space. They last only a fraction of a second but release as much energy as the sun emits in three days. They were first discovered in 2007, and much remains unknown about them.

Webb's near-infrared instruments detected a galaxy in the location from which the burst had come. Based on measurements of the way the galaxy's light stretches, the burst occurred just 3 billion years after the Big Bang. Its origin galaxy existed when star formation was at its peak in the universe. The galaxy that produced the burst is also 1,000 times smaller than expected. Previous fast radio bursts detected by astronomers took place billions of years later, in massive, star-forming galaxies.

There are a couple of theories about how fast radio bursts are produced. One proposes that they are generated by the merger of two neutron stars. But two neutron stars, the collapsed cores of massive supergiant stars, take billions of years to collide. That means bursts from such mergers could come only from older galaxies. Another theory suggests the bursts can come from massive stars exploding in a supernova and leaving behind magnetars, a rare type of neutron star with highly powerful magnetic fields.

"Our work suggests that it's very unlikely that this [fast radio burst] was produced by a merger," said Manisha Caleb from the University of Sydney in Australia. Caleb served as lead author on the study published in Science. The work indicates that the origin of this burst was likely a supernova, providing support for the theory that fast radio bursts can come from a certain type of star explosion.