Faraday rotation measure RM (colour) between λ6.2 cm and λ3.6 cm at 3′ HPBW, calculated at pixels where PI at both frequencies exceeds three times the rms noise. The error decreases from 93 rad m⁻² at S/N = 3 to about 9 rad m⁻² at the highest S/N. Contours show the polarized intensity at λ6.2 cm at the same resolution. Contour levels are at 0.5, 1, and 2 mJy beam⁻¹. Polarized background sources have been subtracted. The HPBW is indicated in the bottom left corner. The coordinate system is rotated by −53°.