Left: mean RM map corresponding to the red line in the right panel. Color plot: binned RM values (logarithmic color scale from −25 to +25 rad m⁻²). Thick white line: elliptical region where most bins contain contributions from several galaxies. Thick green line: horizontal extent of edge-on rescaled 22 μm infrared disk. Thin dotted lines: 15° angular sectors around the center. Right: red line: mean RM distribution around the center of the mean CHANG-ES galaxy inside the white ellipse on the left (see text for details). Angles measured clockwise from the left horizontal semi-axis. The alternating gray and white colors of the background indicate the four quadrants of the mean RM map. 100 thin black lines: similar to red line after random rotation of half the sample of the aligned galaxies by 180°. The underlying universal pattern survives, on average, after these random 180° rotations.