Normalized probability distribution with cluster-centric distance. Only sources with Hα luminosities between 10⁴⁰ and 10⁴² erg s⁻¹ are included. We separate sources into four classes, based on their parent cluster type and the powering source of the Hα emission (SF or AGNs). The radial distribution of star-forming galaxies and AGNs is different between relaxed and merging clusters. The bulk of SF and AGN activity in merging clusters is happening within 3 Mpc of the cluster core. By contrast, the bulk of emission-line galaxies in relaxed clusters are located outside the core (>1.5 Mpc).