Scatter plot of S (dispersion function of ) as a functionof I (top) and PF (bottom) for data points with SNR(I) > 25 and SNR(PI) > 3 (cf., Fig. 7). The data points with 50 < PI < 100 mJy beam⁻¹ and PI > 100 mJy beam⁻¹ are shown in yellow and red, respectively. The black solid curves show the median log(S) per bin of log(I) and log(PF) in the top and bottom panels, respectively. The lower and the upper dashed black lines are the 16% and 84% percentiles of the distributions, respectively. The red horizontal line at S = 52° shows the value that S would take for a B-field dominated by turbulence. Bottom panel: cyan solid line is a linear fit to the distribution.