Fast radio bursts (FRB) are sudden, intense bursts of radio wave energy from deep space that remain one of the most intriguing mysteries of astrophysics, and a new study adds valuable insight into what might be creating them.

Researchers led by a team from the Italian National Institute of Astrophysics (INAF) studied FRB 20201124A, which was first discovered in 2020. They specifically analyzed the persistent radio source (PRS) near the FRB.

These PRS signals have been detected near a small number of FRBs and may be closely related to them. Here, PRS measurements showed that they most likely originate from a plasma bubble surrounding the mysterious FRB source. This plasma bubble is called an ionized nebula, which is a cloud of electrically charged (ionized) gas and dust.

“In particular, using radio observations of one of the flares closest to us, we were able to measure the weak persistent emission from the same location as the FRB, expanding the range of radio flux investigated for these objects by up to two orders of magnitude,” says astrophysicist Gabriele Bruni from INAF.

The data collected included observations from the Very Large Array (VLA) radio telescope in New Mexico and suggests that the nebula could be the result of a young magnetar (an extremely intense ultramagnetic star), a neutron binary, a star (leftover from a supernova), or a black hole.

The team says any one of these celestial events could generate a large enough amount of energy to trigger the FRB signals observed by the system. The result could also create a surrounding nebula, a bubble of plasma that is predicted to be responsible for the background hum of the PRS.

There are still questions to be answered about FRB 20201124A, but the study gives us a much better idea of ​​some pieces of the puzzle. Other FRBs are likely to form in different ways, but at least in this case we are getting closer to an explanation.

“The high-resolution data tells you first of all that star formation is not spread over a large region of the host galaxy where you would expect it to be,” says astrophysicist Brendan O’Connor of Carnegie Mellon University in the US.

“Second, it allows you to constrain the actual size of the source. And given the assumed size, it fits the big picture of what you would expect from a magnetar nebula.”

More data was collected using the Northern Extended Millimeter Array (NOEMA) and Gran Telescopio Canarias telescopes, allowing researchers to determine how much energy the system emits in each wavelength of light, a key part of decoding signals from a billion light-years away.

“New data were obtained at radio wavelengths with better angular resolution than previous studies,” O’Connor says.

“You’re actually looking at something as 1080p rather than 720p. And in that case, the higher resolution image allows us to better localize what’s happening in that source.”

The study was published on: Nature.