Extended Data Fig. 2: Before and after calibrating the polarisation data of PSR B2111+46.
From: Highly polarized microstructure from the repeating FRB 20180916B
The average polarisation profiles (panels b and d) and polarisation position angle (panels a and c) of PSR B2111+46. Black represents the Stokes I profile, red is the unbiased linear polarisation profile (defined in Everett & Weisberg29, and rewritten here in Equation 1), and blue is the circular polarisation (Stokes V) profile. Panels a and b show the polarisation profile and position angle after Faraday-correcting to the true rotation measure79 of PSR B2111+46 (-218.7 rad m−2); here we are not correcting for the instrumental delay between polarisation hands. Panels c and d are Faraday-corrected with the rotation measure determined using the PSRCHIVE tool rmfit, which, in essence, accounts for the instrumental delay. For comparison, we plot the profile and position angle from the literature using more transparent colours80. This illustrates the calibration we applied to the bursts from FRB 20180916B.
