Astronomers Trace Farthest Fast Radio Burst to Distant Galaxy

Astronomers have detected FRB 20240304B, the most distant fast radio burst recorded so far, using the MeerKAT radio telescope in South Africa and NASA’s James Webb Space Telescope to locate its host galaxy from when the universe was about 3 billion years old.

The discovery, published in Science, shows the millisecond radio signal traveled for more than 10 billion years, allowing researchers to study matter across about 80% of cosmic history. NASA reported the burst was detected by the MeerTRAP team on MeerKAT.

The Webb telescope identified a small host galaxy with a redshift of 2.148. According to NASA, the galaxy is about 1,000 times less massive than expected for a typical FRB host and is actively forming stars with low metal content.

Researcher Themiya Nanayakkara of the University of Sydney described the early cosmic timing of the event.

"There was no Earth, there was no sun" said Themiya Nanayakkara, researcher at the University of Sydney.

Fast radio bursts are intense radio flashes first discovered in 2007. Scientists continue to study whether they are produced by magnetars or other energetic events.

"What makes fast radio bursts interesting is that we don't know what generates them. We have theories for what objects produce them, but we don't have conclusive proof" said Manisha Caleb, lead author from the University of Sydney.

Caleb said the host galaxy differed from many previously identified FRB environments because it was small and undergoing rapid star formation.

"We thought it would be a big, nicely formed galaxy with lots of stars, and instead it was a little dwarf galaxy, although it was actively forming stars" said Manisha Caleb, lead author from the University of Sydney.

Ben Stappers of the University of Manchester noted the unusual nature of the host galaxy found by the team.

"The host sticks out in the whole galaxy sample that we have. And it definitely was not what we were expecting" said Ben Stappers, co-author from the University of Manchester.

The research team combined radio observations from MeerKAT with Webb’s infrared imaging and spectroscopy to confirm the burst’s origin.

"This combination of using the MeerTRAP project on the MeerKAT telescope to discover and localize these distant bursts and Webb to study their hosts is very exciting" said Ben Stappers, co-author from the University of Manchester.

The findings support theories that some FRBs may come from young magnetars formed after massive stars collapse, rather than from neutron star mergers that require longer timescales.

"Our work suggests that it’s very unlikely that this FRB was produced by a merger" said Manisha Caleb, lead author from the University of Sydney.

Nanayakkara said Webb’s observations expanded scientists’ ability to study distant cosmic events.

"Our results further show the amazing capability of Webb where we can push boundaries beyond what was previously possible" said Themiya Nanayakkara, co-author from the University of Sydney.

The burst also provided information about invisible matter along its path through space, including structures in the cosmic web.

"A fast radio burst is almost like a cosmic flashlight. It lights up everything along the path. It carries an imprint of everything that it travels through" said J. Xavier Prochaska, co-author from the University of California, Santa Cruz.

The researchers found evidence of cosmic structures affecting the signal, including a previously unknown galaxy cluster at a redshift of 0.3 and the nearby Virgo Cluster.