A Unified Volumetric Rate-Energy Relation from Magnetar Radio Bursts to Fast Radio Bursts

TL;DR

This paper finds a unified relation between the volumetric rate and energy of radio bursts from magnetars and FRBs, supporting the idea that magnetars are the common progenitors of both repeating and non-repeating FRBs.

Contribution

It establishes a universal rate-energy relation across a wide energy range, linking magnetar radio bursts and extragalactic FRBs, which was previously uncertain.

Findings

Similar rate-energy relation for magnetar bursts and FRBs

Power-law index $eta=1.31$ indicating a common origin

Supports magnetars as progenitors for all FRB types

Abstract

Fast radio bursts (FRBs) are millisecond radio pulses with extremely high bright temperature. Their physical origin is still a mystery. The discovery of FRB 20020428 supports the idea that at least a portion of FRBs is generated by magnetars. However, FRB 20200428 and other radio bursts of SGR 1935+2154 are much less energetic than that of extragalactic FRBs. Thus, whether the progenitors of extragalactic FRBs are magnetars is still in controversy. Here, we investigate the volumetric rates of radio bursts from SGR 1935+2154, non-repeating FRBs and FRB 20180916B using the uniform samples detected by the Canadian Hydrogen Intensity Mapping Experiment (CHIME). We find that they share a similar relation between the volumetric rate $R$ and the burst energy $E$, i.e., $R\propto E^{-\gamma}$ with $\gamma=1.31\pm 0.13$ from $10^{29}$ erg to $10^{42}$ erg. Our results support the hypothesis that both repeating and non-repeating FRBs originate from magnetars.