Understanding the role of compact star formation in galaxy evolution

Massive elliptical galaxies in the local universe appear to have their high-redshift analogues in the form of extremely compact quiescent galaxies. Therefore, it seems that compact star formation appears to play a pivotal role in the evolutionary pathways of massive galaxies across cosmic history. However, there are fundamental unresolved questions debated in the literature: How systematic is compact star formation in star-forming galaxies at high redshift? What is its role in the broader picture of the scaling relations in galaxy evolution? I will present the latest results of the GOODS-ALMA survey, a 1.1mm ALMA survey aimed to tackle these questions. Compact star formation appears to be the norm in massive star-forming galaxies at high redshift and sizes as extended as typical star-forming stellar disks are rare. It unveils as a physical driver of the behaviour of massive star-forming galaxies in the scaling relations. The new findings suggest that compact star formation is fundamental in keeping galaxies as star forming systems even when their gas to fuel star formation is very low and they are presumably on their way to quiescence.