Angular distribution on the plane of the sky of critical points that are affected by edges. The top panel refers to the Legacy MGS and the bottom panel to LOWZ+CMASS. In each panel all the critical points detected by DisPerSE are shown with filled circles, colour-coded according to their type. Cyan stars highlight critical points that are affected by edges (including bifurcations, see text). As an example, the 3σ persistence skeletons have been chosen, with one smoothing cycle of the density field in the Legacy MGS case and no smoothing at all of the density field in the LOWZ+CMASS case.