A universal energy distribution function for repeating fast radio bursts?

TL;DR

This paper proposes a universal energy distribution function for repeating fast radio bursts, consistent with observations, and explores its implications for understanding FRB populations and their energy characteristics.

Contribution

It introduces a universal power-law energy distribution function for repeating FRBs and constrains its parameters based on observational data.

Findings

FRB energy distribution follows a power-law with index 1.5 to 2.2

High-end cutoff energy E_max is at least 30 times the reference energy

Estimated FRB rate normalization is less than 2 per day

Abstract

Assuming: fast radio bursts (FRBs) are produced by neutron stars at cosmological distances; FRB rate tracks core-collapse supernova rate; and all FRBs repeat with a universal energy distribution function (EDF) dN/dE ~ E^(-beta) with a high-end cutoff at burst energy E_max. We find that observations so far are consistent with a universal EDF with a power-law index 1.5 < beta < 2.2, high-end cutoff E_max/E_0 > 30 and normalization N_0 < 2 per day; where N_0 is the integrated rate above the reference burst energy E_0 = 1.2e39 f_r^(-1) erg (f_r is the radio emission efficiency). Implications of such an EDF are discussed.