Tracing Starbirth in the Shadows Exploring Radio-selected NIR Dark Galaxies to study the Star Formation Rate Density

The exploration of galaxy formation and evolution is a pivotal area in astrophysics, with the star formation rate density (SFRD) being a critical measure. Traditional optical and UV surveys for studying SFRD are now questioned for potentially overlooking dust-obscured galaxies, which could play a significant role in understanding galaxy formation. This thesis focuses on identifying dust-obscured star-forming galaxies (DSFGs) in the J1030 field using a selection criterion based on radio emissions as a dust-unaffected star formation rate (SFR) indicator. It introduces an enhanced version of PhoEBO, a pipeline for deblending NIR-Dark galaxies in MIR-to-FIR maps, and employs a new technique for deblending in sub/mm bands. Characterization of these galaxies through SED fitting reveals a population of DSFGs extending from z=0 to z=2-3 (the so-called 'cosmic noon'), with some reaching z>5, and highlights their contribution to the SFRD. This contribution is estimated between 3% at z=2 and 13% at z=3, but these values are only lower limits, underscoring the potential underestimation by optical and UV surveys of a significant galaxy population. The study also suggests DSFGs as possible progenitors of massive quiescent galaxies at z=2 given their number densities, challenging current simulations and enhancing our understanding of galaxy evolution.