Fast radio bursts (FRBs) were first discovered over ten years ago, and since their discovery, scientists have worked to figure out what could be generating the intense flashes of radio waves. Researchers have used a gradual process of elimination, and the field of possible explanations for FRBs has been narrowed as new information about them was gathered. The type of information researchers have been gathering includes how long the FRB lasts, the frequencies of the radio waves detected, and other tidbits.
Researchers led by scientists from McGill University have established that FRBs include radio waves at frequencies lower than were detected before. The team says the discovery changes the boundaries for theoretical astrophysicists trying to determine the FRB source. Researcher Ziggy Pleunis says that the team detected vast radio bursts down to 110 MHz. Previously, FRBs were only known to exist down to 300 MHz.
The researcher says that the discovery shows that the region around the source of the bursts could be transparent to low-frequency emissions. Some theories had suggested all the low-frequency emissions would be absorbed right away and would therefore never be detected. In their study, the scientists focused on an FRB source that was first detected in 2018 using the CHIME radio telescope in British Columbia.
The FRB is known as FRB 20180916B and was of particular interest to researchers because it’s relatively close to Earth and emits FRBs at regular intervals. Researchers used CHIME and observations from another radio telescope called LOFAR in the Netherlands. Using both tools, the team was able to detect the remarkably low FRB frequencies and discovered a consistent delay of around three days between higher frequencies being picked up by CHIME and the lower frequencies reaching LOFAR.
The team says that delay rules out explanations for the periodic activity that doesn’t allow for the frequency dependence. This brings the team a few steps closer to lending the original of the bursts.