Effects of localisation precision on identified fast radio burst host galaxy magnitudes

Abstract: We study the potential bias in the identification of fast radio burst (FRB) host galaxies due to radio localisation uncertainty. Using a sample of FRBs localised to typically 0.5'' by the Australian Square Kilometre Array Pathfinder (ASKAP), we artificially increase the localisation uncertainty up to 10'', and re-run the Probabalistic Association of Transients to their Hosts (PATH) algorithm to determine the most likely host galaxy. We do not find evidence of a significant change in identified hosts until the localisation precision is worsened to 2'' or greater.