A research team led by Prof. Li Di from the NAOC has discovered circular polarization in active repeating fast radio bursts.
The findings were published in a journal.
A fast radio burst is a radio flash in the universe. The equivalent energy of a single event can rival the output of the sun over a long period of time.
More than 600 FRB sources have been found since the first one was reported in 2007. Less than 5% of all FRBs have repeated bursts.
One of the basic properties of the waves is their polarization. Unpolarized light is one of the many common light sources. Almost all repeating FRBs have been found to have linear polarization. Circular polarization isn't very common. The only repeating FRB that has been reported is FRB202011 24A.
The first repeater is called FRB 20121102A. The first persistently active repeater is found by the Commensal Radio Astronomy FAST Survey. They are the only repeaters found to be associated with persistent radio sources, which may be a sign of their youthfulness. Fast was able to capture episodes that were very active for the two FRBs.
The researchers found less than 5% of the bursts from the two FRBs. There was a maximum degree of circular polarization. Multi-path propagation is the reason for the large degree of circular polarization. There are currently viable hypotheses, including a radiation mechanism.
Circular polarization is more likely to occur in non-repeaters than in repeaters. It should be less likely that the conditions for generating circular polarization are present.
There is an increase in the number of repeating FRBs. Circular polarization may be a common trait in repeating FRBs, despite the fact that it occurs occasionally.
New light on the emission mechanism of FRBs will be shed by further systematic and precise characterization by FAST.
There is more information in the Science Bulletin. The article is titled "Scib.2022.11.014".
All Rights Reserved © 2024
