NAOC’s Dr. Scientists led by Dee Lee discovered an extreme field inversion around the Fast Radio Burst FRB 20190520B, indicating that the signal could pass through a turbulent magnetized plasma field. This discovery brings us closer to understanding the origin of these intense cosmic explosions that can be associated with black holes or massive stars.

Fast radio bursts (FRBs) are the brightest millisecond-long cosmic bursts in the radio bands. Its unknown origins pose problems for astronomy and physics.

Commensal Radio Astronomy FAST Survey (CRAFTS), a key program of the 500-meter Spherical Radio Telescope (FAST), has discovered the world’s first continuously active repeating FRB, known as FRB 20190520B. This FRB has now provided clues that can help clarify the origin of the FRB.

From the National Astronomical Observatory of the Chinese Academy of Sciences (NAOC), Dr. An international team led by Di Li conducted a monitoring campaign for FRB 20190520B using the Parkes Telescope in Australia and the Green Bank Telescope (GBT) in the United States. . Combined analysis revealed an extraordinary field reversal around this continuous explosive source.

The study, based on observations made on three continents, is published in the journalism. Science May 11 Unlike all other FRBs, FRB 20190520B produces bursts that can be detected by at least one and sometimes several telescopes each time it is observed. This robustness makes it an ideal target for multi-band monitoring observational studies.

“A total of 113 bursts from FRB 20190520B have been detected by the Parkes telescope, exceeding the total number of fast radio bursts previously detected at Parkes, highlighting the value of FRB 20190520B,” said Dr Shea Dyfe of PI Western Sydney University. of the FRB 20190520B project in Parkes.

With a combined analysis of data from GBT and Parkes, Dr. Yi Feng, Ph.D., NAOC, and Ms. Anna-Thomas of West Virginia University (WVU) measured the polarization properties and found that the degree of rotation of Faraday’s (RM) significantly changes its sign twice: from ~10,000 units to ~-10,000 units. and vice versa. Other key contributors include Caltech’s Dr. Liam Connor and WVU’s Dr. Sarah Burke-Spolaor.

During the propagation of the explosive signal, the polarization properties can be affected by the surrounding plasma. “RM can be estimated by the integral product of the magnetic field and electron density. RM variations can be caused by any factor, but the change in sign must be due to changes in magnetic fields because electron density cannot be negative,” said study author Dr. Di Lee.

This reversal may be the result of propagation across a turbulent magnetized plasma screen located 10 meters away.^-5 Up to 100 parsecs from the FRB source. “The turbulent components of the magnetic field around the repetitive fast radio emissions can be as diffuse as a ball of wool,” said Professor Yuanpei Yang of Yunnan University, co-author of the study.

One possible scenario for creating such confusion involves the signal passing through an accompanying halo, whether it’s a black hole or a large windy star. Understanding the dramatic changes in the magnetized environment around FRBs is an important step towards understanding the origin of such cosmic explosions.