Highly polarised microstructure from the repeating FRB 20180916B

Understand

Fast radio bursts (FRBs) are bright, coherent, short-duration radio transients of as-yet unknown extragalactic origin.

• FRBs exhibit a wide variety of spectral, temporal and polarimetric properties, which can unveil clues into their emission physics and propagation effects in the local medium.
• Here we present the high-time-resolution (down to 1 $\mu$s) polarimetric properties of four 1.7-GHz bursts from the repeating FRB 20180916B, which were detected in voltage data during observations with the European VLBI Network (EVN).
• We observe a range of emission timescales spanning three orders of magnitude, with the shortest component width reaching 3-4 $\mu$s (below which we are limited by scattering).