A new discovery sheds light on how fast radio bursts (FRBs) are produced, events that can carry enormous amounts of energy and outshine entire galaxies.
A team from the Massachusetts Institute of Technology (MIT) has made a significant step in understanding the nature of fast radio bursts (FRBs), which are short-lived and intense bursts of radio waves emitted by extremely compact objects such as neutron stars and possibly black holes. These events last only a thousandth of a second but can carry enormous amounts of energy, enough to briefly outshine entire galaxies.
Researchers have used a new technique to determine the origin of one of the FRBs, and their results provide the first definitive evidence that these phenomena can originate from the magnetosphere of a neutron star.
“We found that the energy stored in the magnetic fields of a neutron star can be emitted as radio waves detectable halfway across the universe. In these neutron star environments, the magnetic fields are at the limit of what the universe can produce,” says Kiyoshi Masui, a professor of physics at MIT.
The MIT team used data from the CHIME radio telescope to analyze FRB 20221022A, which was detected in 2022. They found that the light from the burst was highly polarized, suggesting that the FRB source is rotating.
“This discovery is a breakthrough in our understanding of FRBs. We now know that these phenomena can occur in the magnetosphere of a neutron star, which will help us better understand the physical processes that drive them,” says Kenzie Nimmo, a postdoc at MIT’s Kavli Institute for Astrophysics and Space Research.
The scientists also found that FRB 20221022A originated in a region extremely close to the rotating neutron star, at a distance of no more than 10,000 kilometers. At such a close distance, the burst most likely originated from a highly magnetic region immediately surrounding the ultra-compact star.
“Zooming out to a 10,000-kilometer region from 200 million light-years away is like measuring the width of a DNA double helix, which is about 2 nanometers, on the surface of the moon,” Masui says.
The team’s results, combined with findings from the McGill University team, rule out the possibility that FRB 20221022A originated on the outskirts of a compact object. Instead, the scientists believe that fast radio bursts can originate very close to a neutron star in highly chaotic magnetic environments.
“These bursts happen frequently—CHIME detects several a day. There may be a lot of diversity in how and where they occur, and this scintillation technique will be really useful in elucidating the different physical processes that drive these bursts,” Masui added.
