Two-dimensional distribution function of and polarization fraction p_MAS for the Polaris Flare maps (left), for the model maps using the best fitting parameters averaged over 60 realizations (middle), and residuals (right). The polarization angle dispersion function is computed at a lag δ = 16′. The solid black line shows the mean for each bin in p_MAS and the dashed black line is a linear fit of that curve, restricted to bins in p_MAS which contain at least 1% of the total number of points (120 × 120).