Separation distribution for cross-matched catalogue and for spurious matches from cross-matching with randomized catalogues for the Wen et al. (2012) catalogue (left; blue and dark blue) and Rykoff et al. (2014) catalogue (right; red and dark red). Note that the y axis is cropped to show the distribution at large distances: the bin encompassing zero separation in both catalogues extends to much higher values (630 for the left-hand and 232 for the right-hand panel) – these are sources for which the AGN host and cluster centre galaxy are the same.