Scientists have uncovered more details about perhaps the most famous replay fast radio burst, a mysterious phenomenon that astronomers cannot yet explain.
Astronomers first saw this fast radio burst, known as FRB20180916B, in 2018, just over a decade after FRBs were first discovered. Although some FRBs are single flashes at night, some cycle rhythmically and again; this particular FRB falls into the latter category, exploding for four days and then silent for 12. It is also the closest FRB scientists have seen so far, “only” 500 million light-years away.
The combination of frequent and close makes it a particularly attractive FRB to study, and two teams of researchers recently did so.
Related: The 10 strangest things in space
One team used dozens of detections made by Low frequency matrix (LOFAR) in Europe and the Canadian Hydrogen Intensity Mapping Experiment (CHIME) to examine the wavelength range of radio waves produced by the FRB. The researchers were able to collect emissions from FRB20180916B using LOFAR that were three times longer (with three times less frequency) than previously observed emissions from the same FRB.
“This tells us that the region around the source of the bursts must be transparent to low-frequency emissions, while some theories suggested that all low-frequency emissions would be absorbed immediately and could never be detected,” said Ziggy Pleunis, physicist at McGill University in Canada and lead author of one of the new studies, said in a statement.
Furthermore, these particularly long wavelengths from the FRB took longer to cross the great distance from the FRB source to the detectors on Earth. For each rhythmic burst, LOFAR detected longer radio waves approximately three days after CHIME detected shorter radio waves.
“This systematic delay rules out explanations for periodic activity that do not allow for frequency dependence and thus takes us a few steps closer to understanding the origin of these mysterious explosions,” said Daniele Michilli, a co-author of the paper and another physicist. at McGill, he said in the same statement.
The second new article on this FRB is based on the observations collected by the Very long baseline interferometry Network. The research uses a characteristic of light called polarization encoded within four of the FRB bursts to study how the light changes with each pulse over time.
Previous research had found FRB pulses that varied on a scale of 30 microseconds, or millionths of a second. But the new research shows that at least for this particular FRB, some facets of the signal last only a few microseconds, even when other features develop over longer timescales.
Scientists hope that all of these new observations can help narrow the range of theories behind the causes of FRBs. In particular, the researchers of the first paper propose that their study points to a scenario in which a superdense magnetic stellar corpse called magnetar it is interacting with a large companion star with at least 10 times the mass of our sun. In that scenario, the FRB would be produced when the stream of charged particles flowing from the companion star “combs” through the magnetically governed area around the magnetar.
Whether that theory holds will depend on future observations of FRB20180916B.
The research is described in articles published in journals Nature astronomy on March 22nd and The Astrophysical Journal Letters April 9th.
Email Meghan Bartels at [email protected] or follow her on Twitter @meghanbartels. follow us on Twitter @Spacedotcom and on Facebook.