Modeling the Multi-Wavelength Universe: The Assembly of Massive Galaxies

Abstract

Pan-chromatic galaxy surveys are providing tightening constraints on the global mass assembly history, and high-resolution imaging of large fields is telling us when and where stars were formed. How well are state-of-the-art hierarchical galaxy formation models currently doing at reproducing these observations? I present results here that suggest that hierarchical models are doing quite well at reproducing the global star formation and stellar mass assembly history obtained from galaxies selected in the optical and Near IR. However, the same models fail to reproduce two very important populations at high redshift: quiescent red spheroids and vigorously star-forming, dust-enshrouded starbursts. This mismatch carries important lessons about how star formation is triggered and regulated in early galaxies, and may force us to consider new ideas about the formation of massive spheroids.