How else can we detect Fast Radio Bursts?

TL;DR

This paper explores potential electromagnetic signals associated with Fast Radio Bursts (FRBs), focusing on magnetar models that could produce observable optical and high-energy counterparts, and discusses observational strategies to detect these signals.

Contribution

It identifies specific electromagnetic counterparts to FRBs in magnetar scenarios and proposes observational methods to detect these signals across different wavelengths.

Findings

Magnetar giant flares can produce optical flashes and high-energy afterglows.

Prompt optical flashes may reach naked eye luminosity for milliseconds.

Coordinated multi-wavelength surveys can improve detection prospects.

Abstract

We discuss possible electromagnetic signals accompanying Fast Radio Bursts (FRBs) that are expected in the scenario where FRBs originate in neutron star magnetospheres. For models involving Crab-like giant pulses, no appreciable contemporaneous emission is expected at other wavelengths. Magnetar giant flares, driven by the reconfiguration of the magnetosphere, however, can produce both contemporaneous bursts at other wavelengths as well as afterglow-like emission. We conclude that the best chances are: (i) prompt short GRB-like emission; (ii) a contemporaneous optical flash that can reach naked eye peak luminosity (but only for a few milliseconds); (iii) a high energy afterglow emission. Case (i) could be tested by coordinated radio and high-energy experiments. Case (ii) could be seen in a coordinated radio-optical surveys, \eg\ by the Palomar Transient Factory in a 60-second frame as a transient object of $m=15-20$ magnitude with an expected optical detection rate of about 0.1~hr$^{-1}$, an order of magnitude higher than in radio. Shallow, but large-area sky surveys such as ASAS-SN and EVRYSCOPE could also detect prompt optical flashes from the more powerful Lorimer-burst clones. The best constraints on the optical-to-radio power for this kind of emission could be provided by future observations with facilities like LSST. Case (iii) might be seen in relatively rare cases that the relativistically ejected magnetic blob is moving along the line of sight.