New Insights into the Criteria of Fast Radio Burst in the Light of FRB 20121102A

Understand

The total event number of fast radio bursts (FRBs) is accumulating rapidly with the improvement of existing radio telescopes and the completion of new facilities.

• Especially, the Five-hundred-meter Aperture Spherical radio Telescope (FAST) Collaboration has just reported more than one thousand bursts in a short observing period of 47 days \citep{LiD2021}.
• The interesting bimodal distribution in their work motivates us to revisit the definition of FRBs.
• In this work, we ascribe the bimodal distribution to two physical kinds of radio bursts, which may have different radiation mechanisms.