The role of mergers in galaxy evolution

Abstract

The evolution of galaxies has been driven by galaxy-galaxy collisions on all cosmological time-scales, from the primordial universe to the present. In this context, nearby mergers serve as local analogs to gain insight into the physical processes that lead to the formation and trans-formation of galaxies in the more distant universe. Here I review multiwavelength observations -with particular emphasis on recent results obtained with ISO-of mergers of massive galaxies driving the formation of: 1) luminous infrared galaxies, 2) elliptical galaxy cores, 3) luminous dust-enshrouded extranuclear starbursts, 4) symbiotic galaxies, and 5) tidal dwarf galaxies. The most important implication for future studies on the formation of galaxies at early cosmological timescales is that the most luminous galaxies in the local universe (z≤0.1) emit the hulk of their energy in the mid and far-infrared, and therefore, their analogs in the more distant universe would be invisible in the ultraviolet and optical wavelength rest-frames.