The parallelism between galaxy clusters and early-type galaxies: II. The scaling relations

In this second work dedicated to the observed parallelism between galaxy clusters and early-type galaxies we have analyzed the most popular scaling relations shared by these systems. The comparison, based on the data of the WINGS survey, has shown that galaxy clusters at z~0 follow the same L-sigma relation of early-type galaxies and that both in the Ie-Re and M-R planes they are distributed along the sequence defined by the brightest early-type galaxies. The galaxies extracted from the Illustris numerical simulations reproduce quite well the observed distribution of the bright objects in these planes, but dwarfs and clusters are not in their real location. However, by following the progenitors of present day objects up to z=4, they permit to reveal the complex evolutionary paths of galaxies in these diagrams, and indicate that the line marking the Zone of Exclusion, observed both in the Ie-Re and M-R planes, is the trend of fully virialized and passively evolving systems.