A fast radio burst localised to a massive galaxy

TL;DR

This paper reports the precise localization of a fast radio burst (FRB 190523) to a massive galaxy at redshift 0.66, providing new insights into the possible origins of non-repeating FRBs and their host environments.

Contribution

The study presents the first localization of a non-repeating FRB to a massive galaxy, contrasting with previous hosts, and suggests older stellar populations may be involved in FRB production.

Findings

FRB 190523 localized to a massive galaxy at z=0.66

Host galaxy has low star-formation rate compared to the repeating FRB host

Supports diverse galaxy environments for FRB origins

Abstract

Intense, millisecond-duration bursts of radio waves have been detected from beyond the Milky Way [1]. Their extragalactic origins are evidenced by their large dispersion measures, which are greater than expected for propagation through the Milky Way interstellar medium alone, and imply contributions from the intergalactic medium and potentially host galaxies [2]. Although several theories exist for the sources of these fast radio bursts, their intensities, durations and temporal structures suggest coherent emission from highly magnetised plasma [3,4]. Two sources have been observed to repeat [5,6], and one repeater (FRB 121102) has been localised to the largest star-forming region of a dwarf galaxy at a cosmological redshift of 0.19 [7, 8]. However, the host galaxies and distances of the so far non-repeating fast radio bursts are yet to be identified. Unlike repeating sources, these events must be observed with an interferometer with sufficient spatial resolution for arcsecond localisation at the time of discovery. Here we report the localisation of a fast radio burst (FRB 190523) to a few-arcsecond region containing a single massive galaxy at a redshift of 0.66. This galaxy is in stark contrast to the host of FRB 121102, being a thousand times more massive, with a greater than hundred times lower specific star-formation rate. The properties of this galaxy highlight the possibility of a channel for FRB production associated with older stellar populations.