Prediction for the Multi-band Afterglows of FRB 200428 and its Implication

Abstract

Abstract The physical mechanism of fast radio bursts (FRBs) is still unknown. On 2020 April 28, a special radio burst, FRB 200428, was detected and believed to be associated with the Galactic magnetar SGR 1935+2154. It confirms that at least some of the FRBs were generated by magnetars, although the radiation mechanism continues to be debated. To this end, we study in detail the multiband afterglows of FRB 200428 described by the synchrotron fireball shock model. We find the prediction for the optical and radio afterglows of FRB 200428 is consistent with the observations when considering the post-FRB optical and radio upper limits from the literature. We also show that the follow up detection of the afterglows from fast radio bursts like—FRB 200428 is possible at the radio band, though challenging. Based on our model, one can obtain information about the energy of the fireball, the radiation zone, and the nature of the surrounding medium. That may shed light on the physical mechanism of FRBs.