The Environments of Fast Radio Bursts Viewed Using Adaptive Optics

TL;DR

This study uses adaptive optics imaging to analyze the environments of five fast radio burst (FRB) host galaxies, revealing their typical locations in faint, spiral-arm regions with high stellar mass densities, and comparing these environments to other transients.

Contribution

It provides detailed spatial analysis of FRB host galaxies using adaptive optics, highlighting their environmental similarities to core-collapse supernovae and differences from other transient types.

Findings

FRBs are often located in faint, spiral-arm regions of their hosts.

Most FRB hosts show elevated local stellar mass densities.

FRB locations are statistically distinct from Ca-rich transients and SGRBs/LGRBs.

Abstract

We present GeMS/GSAOI observations of five fast radio burst (FRB) host galaxies with sub-arcsecond localizations. We examine and quantify their spatial distributions and locations with respect to their host galaxy light distributions, finding a median host-normalized offset of 2.09 r_e and in fainter regions of the host. When combined with the FRB sample from Mannings et al. (2021), we find that FRBs are statistically distinct from Ca-rich transients in terms of light and from SGRBs and LGRBs in terms of host-normalized offset. We further find that most FRBs are in regions of elevated local stellar mass surface densities in comparison to the mean global values of their hosts. This, in combination with the combined FRB sample trace the distribution of stellar mass, points towards a possible similarity of the environments of CC-SNe and FRBs. We also find that 4/5 FRB hosts exhibit distinct spiral arm features, and the bursts originating from such hosts tend to appear on or close to the spiral structure of their hosts, with a median distance of 0.53 kpc. With many well-localized FRB detections looming on the horizon, we will be able to better characterize the properties of FRB environments relative to their host galaxies and other transient classes.