on galaxy properties. @BOC10 claimed that merging of galaxy clusters may induce SF due to the increase of the external pressure of the ICM compressing the cold gas in the cluster galaxies. This results in a population of starburts or post-starburst galaxies having the same age and so dating the merging event. The spatial distribution of these star-forming galaxies is expected to differ from the overall distribution of the other cluster galaxies. Similarly, for comparable group and cluster halo densities gravitational shocking as the group enters the cluster could temporarily increases its mass and pull the group members into a denser, more compact system inducing galaxy mergers [@Moss06]. Simulations also showed that starbursts induced by galaxy mergers can be amplified by a factor $\sim 2$ [@MB08] if they take place in the tidal field of cluster/group of galaxies.

@OLK05 studied the excess population of radio galaxies in the cluster A2125 at $z$=0.25, mostly located in groups outside the cluster core and with radio luminosities indicating the SF as the main mechanism responsible of the radio emission. The authors related this observational evidence with the ongoing major cluster-cluster merger and explained the increased SF as due to the variation of the 