MIT researchers have zeroed in on the origins of a mysterious cosmic signal known as a fast radio burst (FRB), drawing closer to understanding these space phenomena. According to a report by MIT News, the team used a novel technique centered on the analysis of "scintillation"—a principle akin to the twinkle of stars in our night sky—to pin down the location of FRB 20221022A. This particular burst originated from a galaxy approximately 200 million light-years away.
In their study published in Nature, the MIT scientists establish that the FRB in question likely emanated from a highly magnetic region around a neutron star, no more than 10,000 kilometers away. Despite their usually vast distances, the neutron star they focused on lay within a range comparable to that between New York and Singapore. Kenzie Nimmo, a postdoc from the Kavli Institute for Astrophysics and Space Research at MIT, mentioned, "There’s been a lot of debate about whether this bright radio emission could even escape from that extreme plasma," as reported by MT News.
Understanding FRBs is challenging since they last a mere thousandth of a second and can be launched from highly turbulent environments. The impact of gas and interstellar material on the radio signals—in a process akin to the way light bends as it passes through various media—played a crucial role in the MIT team's investigative process. Associate professor of physics Kiyoshi Masui provided context, telling MIT News, "Around these highly magnetic neutron stars, also known as magnetars, atoms can’t exist — they would just get torn apart by the magnetic fields."
The researchers utilized data from the Canadian Hydrogen Intensity Mapping Experiment (CHIME)—a radio telescope highly adept at catching these cosmic signals—which has discovered thousands of FRBs since 2020. The signal of FRB 20221022A lasted about two milliseconds and was unique in its highly polarized light, suggesting a rotating emission site. This is a characteristic previously observed in pulsars and an implication that the FRB likely originated very close to its celestial source. "Zooming in to a 10,000-kilometer region, from a distance of 200 million light years, is like being able to measure the width of a DNA helix, which is about 2 nanometers wide, on the surface of the moon," Masui explained in the statement obtained by MIT News.
The combined findings from this research dismiss the possibility of FRBs emanating from the outskirts of their celestial sources, pointing definitively to magnetically chaotic environments much closer to neutron stars. This discovery not only pins down the probable source of FRB 20221022A but also holds promise for revealing the origins of more FRBs in the universe. "These bursts are always happening, and CHIME detects several a day," Masui added, as noted by MIT News. The study involved collaboration with multiple institutions and was supported by the Canada Foundation for Innovation, the Dunlap Institute for Astronomy and Astrophysics at the University of Toronto, among others.
