Fast radio bursts (FRBs) erupt in the sky around 10,000 times a day, but scientists have struggled to explain them. New research might bring astronomers closer to a solution.
FRBs are intense, short-lived blasts of radio waves from beyond the Milky Way that can emit as much energy in milliseconds as the sun does in three days. Despite their power, the phenomenon remains largely mysterious. A significant puzzle is why most FRBs flash once and vanish, while a small fraction (less than 3%) repeat. This has led scientists to explore various mechanisms behind FRBs, with some suggesting that different celestial objects could be responsible for the two types.
Researchers from the University of Toronto utilized the Canadian Hydrogen Intensity Mapping Experiment (CHIME) to study polarized light from 128 non-repeating FRBs. This study revealed that these one-off FRBs likely originate in galaxies similar to the Milky Way, rather than the extreme environments that produce repeating FRBs. These findings could help solve the lingering mystery of FRBs.
The study’s lead author, Ayush Pandhi, a Ph.D. student at the Dunlap Institute for Astronomy & Astrophysics, emphasized the unique approach of examining polarized light, which is oriented in a specific direction. This method can provide insights into the mechanisms launching the FRBs and the environments they traverse.
Historically, non-repeating FRBs have been harder to study due to their unpredictable nature. However, CHIME’s ability to observe large sky areas simultaneously has been advantageous. Previous studies looked at the polarization of only a few non-repeating FRBs, but this research analyzed over 100, allowing for a better understanding of their differences from repeating FRBs.
The findings suggest that non-repeating FRBs come from less extreme environments with weaker magnetic fields compared to their repeating counterparts, which are often linked to the remains of supernova explosions.
This research also indicates that highly magnetized, rapidly spinning neutron stars, known as pulsars, may not be the source of non-repeating FRBs, as previously thought. The polarization patterns observed differ significantly from those expected from pulsars.
The study lays the groundwork for future investigations, with Pandhi working on methods to distinguish between the polarization of FRBs occurring in the Milky Way and those from other galaxies. Understanding these differences could help narrow down the possible mechanisms behind FRBs.
