A search for optical transients associated with Fast Radio Burst 150418

TL;DR

This study searched for optical variability in the host galaxy of FRB 150418 to identify potential optical counterparts or active galactic nucleus activity, finding no significant changes over a year.

Contribution

It provides the first optical variability constraints for the host galaxy of FRB 150418, limiting possible optical counterparts and AGN activity.

Findings

No optical variability detected between one day and one year after the burst.

Limits set on optical luminosity of potential counterparts and AGN activity.

Supports the transient nature of the FRB without persistent optical emission.

Abstract

We have searched for optical variability in the host galaxy of the radio variable source which is possibly associated with fast radio burst (FRB) 150418. We compare images of the galaxy taken 1 day after the burst using Subaru/Suprime-Cam with images taken $\sim$ 1 year after the burst using Gemini-South/GMOS. No optical variability is found between the two epochs with a limiting absolute magnitude $\gtrsim -19$ (AB). This limit applies to optical variability of the putative active galactic nucleus in the galaxy on a timescale of $\sim$ 1 year, and also to the luminosity of an optical counterpart of FRB~150418 one day after the burst should it have occurred in this galaxy.