Abstract

Understanding the physical processes driving the formation and evolution of galaxies across the cosmic epochs is one of the most important goals of modern Astrophysics. Observations obtained through major astronomical facilities, together with theoretical modelling and cosmological numerical simulations, have enabled impressive progress in this field. I will present some of the main results obtained in the recent years. In particular, I will shortly review what we know about the infancy of galaxies and the processes responsible for the formation and assembly of stars at different cosmic times. Interestingly, across the entire life of the Universe, these processes managed to convert into stars only 4% of the available baryons, revealing that star formation has been globally very inefficient. Some mechanism must be responsible for regulating star formation in galaxies and preventing them from overgrowing. Some of these mechanisms must be effective enough to completely quench star formation in a significant fraction of galaxies, effectively leading to their “death” (resulting into the large population of local passive and quiescent galaxies). Very interesting is also the finding that additional processes can also “rejuvenate” some of these galaxies and activate new and unexpected channels of star formation. Major progress has been achieved in identifying the key mechanisms responsible for these fascinating phenomena, however several recent puzzling observational findings have yet to be fully understood. Major new astronomical observing facilities are currently being developed; they will certainly enable us to tackle many of the outstanding open questions and are expected to shed new light on the physical mechanisms regulating the formation and evolution of galaxies. Cambridge is heavily involved in these new facilities and I will shortly discuss the plans for their exploitation.