Searching for FRB-like Counterparts from GRBs using the First CHIME/FRB Catalog

Alice Curtin ( Université McGill )

Fast Radio Bursts (FRBs) are a class of highly energetic transient events, lasting for a few milliseconds and originating from extragalactic distances. While over 750 FRBs have so far been published, very little is known about their origins. Some theories for extragalactic FRBs predict accompanying high energy emission, but none has so far been detected. In this work, we use the Canadian Hydrogen Intensity Mapping Experiment (CHIME) Fast Radio Burst (CHIME/FRB) Project to explore whether any FRB-like emission is associated with 69 gamma-ray bursts (GRBs) detected between 29th August 2018 and 2nd July 2019. We do this by searching for any GRBs that are temporally and spatially coincident with FRBs from the first CHIME/FRB catalog. We also search for GRB-FRB pairs within the time frame of the first CHIME/FRB catalog that are solely spatially coincident and find two such pairs, although the chance probability of this occurring is high for our given sample. Lastly, we use CHIME/FRB to constrain FRB-like radio emission before, during, and after the high energy emission for 33 GRBs. Our most constraining radio limits for short gamma-ray bursts (SGRBs) are <20 Jy at 19 ks pre-high-energy emission, and <5 Jy at 28 and 38 ks post-high-energy emission. We use these limits to constrain certain models for radio emission from SGRBs. We also place limits as small as 1 Jy for long gamma-ray bursts (LGRBs), although radio emission associated with LGRBs has not been as strongly predicted.