XXL₃₉ source positions, indicated with crosses, relative to the X-ray identified clusters detailed in XXL Paper II, XXL Paper III, and XXL Paper XX, indicated with shaded circles with radius equal to their r₂₀₀s. When a source overlaps with a cluster, regardless of the source and the cluster’s redshifts, the cluster is shaded in red and its designation from XXL Paper XX is included. The colourbar is used to indicate the rotation measures of the polarised sources.