The spatial distribution of the dust and stars contains crucial information about the evolutionary pathways of galaxies. We present results of our study combing high-resolution ALMA and HST observations of z ∼ 2 bright sub-millimeter galaxies (SMGs). We have developed a two-dimensional extinction and age correction technique to obtain accurate stellar mass distributions from HST/CANDELS. For the first time, we can directly compare the spatial distribution of assembled stellar mass and ongoing star formation on kpc scales for distant SMGs, shedding light on their highly debated formation mechanisms. We find that the dust distribution is more compact than the stellar component, regardless if the SMG lies on the main sequence or at the starburst regime. Taking the dust emission as a proxy for dust-obscured star formation, our results imply that high-redshift SMGs are experiencing centrally enhanced star formation. These findings suggests that major galaxy interactions are not necessarily the main formation channel for SMGs with secular disk formation remaining a viable option as suggested by state-of-the-art cosmological simulations. The sizes and stellar densities of our z ∼ 2 SMGs agree well with the most compact early-type galaxies in the local Universe, strongly supporting the idea that the latter systems are indeed the descendants of massive SMGs at z ∼ 2.

Galaxy morphologies reflect the shapes of galaxies and their structural components, such as bulges, discs, bars, spiral arms, etc. The detailed knowledge of the morphology of a galaxy provides understanding of the physics behind its evolution, since the time of its formation, including interaction processes and influence of the environment. Thus, the more precisely we can describe a galaxy structure, the more we may understand about its formation and evolution. We present a method that measures curvature, using images, to describe galaxy structure and to infer the morphology of each component of a galaxy. We also include some preliminary results of curvature measurements for galaxies of the Southern Photometric Local Universe Survey (S-PLUS) DR1 data release and for jellyfish galaxies of the Omega Survey. We find that the median of the curvature parameter and the integrated area under the curvature give us clues on the morphology of a galaxy.