Galaxies 09: Assembly, Gas Content and Star Formation History of Galaxies

Desika Narayanan
Harvard-Smithsonian Center for Astrophysics

The Infrared Zoo at $z \sim$ 2

Redshift $z \sim$ 2 is perhaps the richest epoch for understanding galaxy assembly. During this era, the bulk of the Universal stellar mass was assembled, and the cosmic SFR density and black hole growth both peak. While it is clear that Infrared-selected galaxies at $z \sim$ 2 appear to be a key player in both forming copious numbers of stars, and growing black holes, the myriad of infrared selection techniques ranging from 24 micron to 1 mm has uncovered a veritable zoo of galaxies (e.g. Dust Obscured Galaxies [DOGs], Submillimeter Galaxies [SMGs], and 1-mm galaxies) whose relationship to one another is unclear. Utilizing a novel combination of high resolution hydrodynamic simulations of galaxy evolution, 3D polychromatic dust radiative transfer calculations and 3D non-LTE molecular line radiative transfer simulations, we will synthesize the plethora of species in this infrared zoo, and provide a merger-driven unifying model connecting DOGs, SMGs, and 1mm selected galaxies. We will discuss the dominant power source as galaxies evolve through their various phases, and assess their relative contributions to both cosmic stellar mass assembly and supermassive black hole growth. If time permits, we will discuss how these galaxies relate to the optically-selected BzK galaxies, and imminently feasible tests of these models with the LMT and/or the IRAM 30m.

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