Multi-wavelength spectral synthesis for galaxy formation?

The Evolutionary Synthesis of Spectral Energy Distribution (SED) of galaxies is now recognized as an essential tool for galaxy evolution. Moreover, by running well calibrated synthesis codes, evolution scenarios are implicitly assuming constraints for theories of galaxy formation. Mass accumulation scales, redshifts of formation and prescriptions for the triggering of star formation are relevant to galaxy evolution as well as to galaxy formation. Hereafter we shall underline the present results of the parameter set for the most massive galaxies. The value of these parameters clearly favor the theory of dissipative gravitational collapses at the earliest epochs (Rees & Ostriker [23]). They leave open the theory by hierarchical merging for less massive galaxies. More investigations at high-z are required to pursue the analysis of evolution scenarios satisfying constraints given by massive ellipticals and by bright spirals at all z. The perspectives of multi spectral surveys hopefully will solve this debated question.