Urumqi λ6 cm maps. Total intensities are displayed as image and contours in the upper panel. Polarisation intensities are displayed as an image in the lower panel, overlaid with bars showing B-vectors (i.e. observed E-vectors rotated by 90) and total intensity contours. The lengths of the bars are proportional to polarisation intensities with a cutoff below 5 × σ_PI. Contours start at 5 mK T_B and run in steps of 10 mK T_B. The gamma-ray pulsar discovered by Fermi (Abdo et al. 2008) is marked as a star. The eastern shell, central branch, and southern shell are sketched by blue dashed lines.