The most probable host of CHIME FRB 190425A, associated with binary neutron star merger GW190425, and a late-time transient search

TL;DR

This study identifies UGC10667 as the most probable host galaxy of a specific FRB, performs multi-wavelength follow-up observations, and discusses potential origins, including neutron star mergers, without detecting any transient afterglow.

Contribution

It confirms the host galaxy of a low-DM, non-repeating FRB and provides multi-wavelength observational constraints on its origin and environment.

Findings

UGC10667 is the likely host galaxy of FRB 20190425A.

No radio or optical afterglow detected 2.5 years post-burst.

Host galaxy shows old stellar population with moderate star formation.

Abstract

The identification and localization of Fast Radio Bursts to their host galaxies has revealed important details about the progenitors of these mysterious, millisecond-long bursts of coherent radio emission. In this work we study the most probable host galaxy of the apparently non-repeating CHIME/FRB event FRB 20190425A -- a particularly high luminosity, low dispersion measure event that was demonstrated by Moroianu et al. 2022 to be temporally and spatially coincident with the LIGO-Virgo-KAGRA binary neutron star merger GW190425, suggesting an astrophysical association (p-value 0.0052). In this paper we remain agnostic to this result, and we confirm UGC10667 as the most probable host galaxy of FRB 20190425A, demonstrating that the host galaxies of low dispersion measure, one-off CHIME FRBs can be plausibly identified. We then perform multi-wavelength observations to characterize the galaxy and search for any afterglow emission associated with the FRB and its putative GW counterpart. We find no radio or optical transient emission in our observations $2.5\,\mathrm{yr}$ post-burst. UGC10667 is a spiral galaxy at $z\sim0.03$, dominated by an old stellar population. We find no evidence of a large population of young stars, with nebular emission dominated by star formation at a rate of $1-2\,\mathrm{M_\odot\,yr^{-1}}$. While we cannot rule out a young magnetar as the origin of FRB 20190425A, our observations are consistent with an origin in a long delay-time neutron star binary merger as posited by Moroianu et al. 2022.