A universal EDF for repeating fast radio bursts?

Abstract

We make three assumptions: fast radio bursts (FRBs) are produced by neutron stars at cosmological distances; FRB rate tracks the core-collapse supernova rate; and all FRBs repeat with a universal energy distribution function (EDF) dN/dE ∝E-β with a cutoff at burst energy Emax. We then find that observations so far are consistent with a universal EDF with 1.5 ≲ β ≲ 2.2, high-end cutoff Emax/E0 ≳ 30 and normalization N0 ≲ 2d-1; where N0 is the integrated rate above the reference energy E0 ≃ 1.2× 1039 fr-1 erg (fr is the radio emission efficiency). Implications of such an EDF are discussed.