Spectropolarimetric analysis of FRB 181112 at microsecond resolution: Implications for Fast Radio Burst emission mechanism

Understand

We have developed a new coherent dedispersion mode to study the emission of Fast Radio Bursts that trigger the voltage capture capability of the Australian SKA Pathfinder (ASKAP) interferometer.

• In principle the mode can probe emission timescales down to 3 ns with full polarimetric information preserved.
• Enabled by the new capability, here we present a spectropolarimetric analysis of FRB 181112 detected by ASKAP, localized to a galaxy at redshift 0.47.
• At microsecond time resolution the burst is resolved into four narrow pulses with a rise time of just $15 \mu$s for the brightest.