Detecting Fast Radio Bursts in the Milky Way

TL;DR

This paper models the detectability of Fast Radio Bursts in the Milky Way, considering interstellar medium effects, and suggests that upcoming all-sky surveys could significantly increase detection rates.

Contribution

It introduces models for Milky Way FRB detection considering ISM effects and evaluates the potential of future surveys like GReX to improve detection rates.

Findings

Detection of Milky Way FRBs is limited by ISM scattering effects.

GReX could increase detection rates by an order of magnitude.

Detection depends on assumptions about FRB luminosity and distribution.

Abstract

Fast Radio Bursts (FRBs) are highly energetic transient events with duration of order of microseconds to milliseconds and of unknown origin. They are known to lie at cosmological distances, through localisation to host galaxies. Recently, an FRB-like event was seen from the Milky Way magnetar SGR 1935+2154 by the CHIME and STARE2 telescopes. This is the only magnetar that has produced FRB events in our galaxy. Finding similar events in the Milky Way is of great interest to understanding FRB progenitors. Such events will be strongly affected by the turbulent interstellar medium in the Milky Way, their intrinsic energy distribution and their spatial locations within the plane of the Milky Way. We examine these effects using models for the distribution of electrons in the ISM to estimate the dispersion measure and pulse scattering of mock events, and a range of models for the spatial distribution and luminosity functions, including models motivated by the spatial distribution of the Milky Way's magnetars. We evaluate the fraction of FRB events in the Milky Way that are detectable by STARE2 for a range of ISM models, spatial distributions and burst luminosity functions. In all the models examined, only a fraction of burst events are detectable, mainly due to the scattering effects of the ISM. We find that GReX, a proposed all-sky experiment, could increase the detection rate of Milky Way FRB events by an order of magnitude, depending on assumptions made about the luminosity function and scale-height of the FRBs.