Fast radio bang: Studies reveal details about the origin

Recent research has found that some FRBs come from magnetars, which are neutron stars with extremely strong magnetic fields. A fast radio blast has been found in the Milky Way and has been linked to a magnetar, according to a 2020 study.

But scientists have yet to determine the origins of the cosmic FRBs, billions of light-years away. It’s a dilemma that has prompted an international team of scientists to see what they can learn from observations of nearly 1,900 bursts from an active fast radioburst source outside our galaxy called FRB 20201124A, according to a study published September 21 was published in Nature.

During the first 36 days, the study team was surprised to see erratic, short-term differences in the Faraday rotation scale, which measures magnetic field strength and particle density in the vicinity of FRB 20201124A. A larger spin scale means the magnetic field near the source of the radio burst is stronger, more intense, or both, and a smaller scale means the opposite, study co-author and astrophysicist Bing Zhang said via email.

“This does not reflect the beginning (of life) of the FRB,” said Zhang, founding director of the Center for Astrophysics at the University of Nevada, Las Vegas. “The FRB source has been there for a long time but has been asleep most of the time. It sometimes wakes up (this time for 54 days) and emits many explosions.”

The scales ramped up and down during this period, then stopped for the last 18 days before the FRB subsided — “indicating that the magnetic field strength and/or intensity along the line of sight near the FRB source varies with time.” “This indicates that the FRB source environment is dynamically evolving, with rapid changes in magnetic fields, density, or both.”

“I’m like filming an FRB source environment, and our film revealed a complex, dynamically evolving magneto environment never imagined before,” Zhang said in a press release.

The researchers found that the radio blast’s complex magneto-environment is within one astronomical unit (the distance between the Earth and the Sun) of its source.

They also discovered that the blast emanated from a narrow, metal-rich spiral galaxy similar to the Milky Way using the 10-meter Keck telescopes in Mauna Kea, Hawaii. The source of the radio burst is located between the galaxy’s spiral arms, where no significant star formation occurs, making it unlikely that the origin was just a magnetar, according to the nature study’s co-author Sobu Dong, associate professor at the Kavli Institute of Astronomy and astrophysics. at Peking University.

“Such an environment is not directly predictable for an isolated magnetar,” Zhang said in a press release. “There could be something else close to the FRB engine, maybe it’s a binary companion.”

The authors said the modeling study should stimulate further research on fast radio burst signals from Be star/X-ray binaries.

“Those notes brought us back to the drawing board,” Zhang said. “FRBs are clearly more mysterious than we imagined. More multi-wavelength observation campaigns are needed to uncover the nature of these things.”