Cross-correlation between sources and events as a function of angular separation for extended (EXT, top-left panel) and point-like (PS, top-right panel) X-ray sources. The lower panels show the masking radius vs. log10 of the counts measured. The average masking radius obtained with the cross-correlation is shown with the black line. The masking radius obtained with eSASS/srctool for individual sources is systematically lower than the black line. Its best-fit polynomial (dashed blue line) is multiplied by 1.2 (extended sources) or 1.4 (point sources) to align with the black line.