A Search for High-energy Counterparts of Fast Radio Bursts

Abstract

The fast radio burst FRB 200428, detected from the Galactic magnetar SGR J1935+2154 together with a contemporaneous X-ray burst, provided the first direct evidence that at least some FRBs originate from magnetars. Whether high-energy emission commonly accompanies other FRBs, however, remains unclear. Here, we perform a systematic search for high-energy counterparts to 336 FRBs from the CHIME/FRB burst catalog using Fermi/Gamma-ray Burst Monitor data in the 8–200 keV and 8–1000 keV bands. We find no statistically significant high-energy signal temporally associated with these events, and a stacked light-curve analysis likewise reveals no significant excess. We therefore derive 1024, 100, and 64 ms upper limits on the associated high-energy emission, typically at the level of ∼10−8–10−7 erg cm−2 s−1. These results place population-level constraints on the associated high-energy emission of FRBs and suggest that any such emission is either intrinsically weak, strongly dependent on geometry or burst conditions, or below the sensitivity of current instruments.