Host galaxies of the two scatter-broadened FRBs detected with ASKAP. The grey ellipse shows the localisation corresponding to the sky area containing the FRB with 90 per cent. From Jahns-Schindler et al. 2026. probability.

Jahns-Schindler et al. report the detection of two highly scattered Fast Radio Bursts (FRBs) with the Commensal Realtime ASKAP Fast Transient COherent (CRACO) backend. FRB 240210D and FRB 240312D have scattering times of 34 ± 6 and 300 ± 48 ms, respectively, when scaled to 1 GHz. Observations with the XShooter spectrograph on the VLT determined the redshift for the host galaxy of FRB 240210D to be z = 0.324. The host galaxy is shown in the left panel above, and shows no discernible structure at the given resolution. FRB 240312D originates near a spiral arm of a face-on galaxy at a redshift of only 0.05, corresponding to a luminosity distance of 230 Mpc. Integral field spectroscopy of the host reveals a Milky Way-like galaxy with a star-formation region at the FRB position. The team find refractive scattering in a pulsar wind nebula as the most likely scattering origin. The rate calculated from the two reported FRBs is consistent with the rate seen at lower widths (roughly 200 FRBs/sky/day). This indicates the presence of a large population of highly scattered FRBs. This elevated rate suggests that the strong scattering seen in other FRBs likewise does not arise from chance-aligned sightlines, but is instead causally linked to the FRB sources. Optical images of the host galaxies are shown above, where the grey ellipse shows the localisation corresponding to the sky area containing the FRB with 90 per cent probability.