Multi-wavelength afterglows of fast radio bursts

TL;DR

This paper models the multi-wavelength afterglows of fast radio bursts to assess their detectability and guide future observational strategies with advanced telescopes.

Contribution

It provides the first detailed calculations of FRB afterglow lightcurves across multiple wavelengths considering various energies and redshifts.

Findings

FRB afterglows are generally too faint for current detectors.

Detectability depends on high kinetic energy and proximity of the FRB.

Future telescopes like LSST and EVLA could observe these faint afterglows.

Abstract

The physical nature of fast radio bursts (FRBs) is not identified. Detecting electromagnetic counterparts in other wavelengths is essential to measure their distances and to settle down their physical nature. Assuming that at least some of them are of a cosmological origin, we calculate their afterglow lightcurves in multi-wavelengths (X-rays, optical and radio) by assuming a range of their total kinetic energies and redshifts. We focus on forward shock emission, but also consider the possibility that some of them might have bright reverse shock emission. In general, the FRB afterglows are too faint to be detected by current detectors. Only if an FRB has a very low radiative efficiency in radio (hence, a very large kinetic energy), and when it is close enough, can its afterglow be detected in the optical and radio bands. We discuss observational strategies to detect these faint afterglows using future telescopes such as LSST and EVLA.