Simulated Planck maps. Top: total gas column density. Middle: polarization fraction and angle, with contours being the column density at values indicated in units of 10²¹ cm^-2, and the bars indicate magnetic orientation. Bottom: angle dispersion function at lag δ = 16′, with the same contours and bars as in the middle row. Left: viewing angle α = 0°. Right: viewing angle α = 90°. In each row, the same colour scale is used. In the lower left corner of each plot (yellow circle) is the 15′ FWHM beam.