Faraday complexity analysis. Top: Comparison between the RM derived with the RM synthesis (x axis) and the λ²-fit techniques applied to the entire mosaic. Each point is the RM at the polarized surface brightness peak of each source. The points are color-coded according to the reduced χ² of the λ²-fit. The bottom right inset shows a histogram of the residuals. Middle and bottom: The red points show the polarized angle as a function of λ². The empty and filled points are, respectively, the observed and the nπ-ambiguity-corrected points. In each plot, the results of the RM synthesis and of the λ²-fitting techniques are reported as dotted and solid lines, respectively. The RM values are also reported in each plot with the value of the reduced χ² when larger than 1.