Astronomers from the Massachusetts Institute of Technology (MIT) and universities in Canada and the United States said they detected a radio signal from a distant galaxy that flashes repeatedly.
In research published in the Journal Nature, authored by members of the Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB collaboration, scientists said that a fast radio burst (FRB) was located several billion years- earth light.
CHIME is an interferometric radio telescope at the Dominion Astrophysical Radio Observatory in British Columbia, Canada. It is designed to detect radio waves emitted by hydrogen in the early stages of the universe, and it has detected hundreds of FRBs.
FRBs are millisecond-long flashes of radio waves that are visible at distances of billions of light-years. The first FRB was discovered 15 years ago; hundreds of similar radio flashes have been detected, although the majority of FRBs seen have been one-time.
The exact source of the FRB, labeled FRB 20191221A, remains a mystery.
Astronomers theorize the repeating signal could come from a magnetar or a radio pulsar – types of neutron stars – “on steroids”. Neutron stars are dense, collapsed cores of giant stars.
However, it is the duration of FRB 20191221A that is most notable.
The radio signal, which was picked up in December 2019, lasts up to three seconds, about 1,000 times longer than the average FRB.
“It was unusual,” Daniele Michilli, a postdoctoral fellow at MIT’s Kavli Institute for Astrophysics and Space Research, said in a statement. “Not only was it very long, about three seconds, but there were remarkably precise periodic peaks, emitting every fraction of a second – boom, boom, boom – like a heartbeat. This is the first time that the signal itself is periodic.
It is currently the most persistent FRB with the clearest periodic pattern to date and the team has detected bursts of radio waves that repeat every 0.2 seconds in a clear pattern.
“The long (about [3-second]) and nine or more components forming the pulse profile make this source an outlier in the FRB population. Such a short periodicity provides strong evidence for a neutron star origin of the event. Additionally, our detection favors emission from the neutron star’s magnetosphere, as opposed to emission regions farther from the star, as some models predict,” the group wrote.
Additionally, FRB 20191221A appears to be more than a million times brighter than radio emissions from our own galactic pulsars and magnetars.
“CHIME has now detected many FRBs with different properties,” Michilli noted. “We’ve seen some that live inside very turbulent clouds, while others seem to be in clean environments. According to the properties of this new signal, we can say that around this source, there is a cloud of plasma which must be extremely turbulent.
The team aims to detect more signals from this source, which MIT says in a statement could be used as an “astrophysical clock” – perhaps even measuring how fast the universe is expanding.
Michilli said future telescopes promise to discover thousands of FRBs per month, which could lead to the detection of “many more of these periodic signals”.
This announcement follows the release of the first images from the James Webb Space Telescope, which date back billions of years.