Introducing cosmosTNG: simulating galaxy formation with constrained realizations of the COSMOS field

Abstract

We introduce cosmosTNG, a first-of-its-kind suite of constrained galaxy formation simulations for the universe at cosmic noon (z ~ 2). cosmosTNG simulates a 0.2 deg² patch of the COSMOS field at z ≃ 2.0-2.2 using an initial density field inferred from galaxy redshift surveys and the CLAMATO Lyα forest tomography survey, reconstructed by the TARDIS algorithm. We evolve eight realizations of this volume to capture small-scale variations. All runs use the IllustrisTNG galaxy formation model with a baryonic mass resolution of 10^6 M☉, equal to TNG100-1. We demonstrate qualitative agreement between the evolved large-scale structure and observed galaxy populations in COSMOS, emphasizing the zFIRE protocluster region. We compare the statistical properties and scaling relations of the galaxy population between cosmosTNG, observations in COSMOS, and z ~ 2 observations in general. Galaxy quenching and environmental effects in COSMOS are modulated by its specific large-scale structure, particularly the collapsing protoclusters. Relative to a random region of the universe, the abundance of high-mass galaxies is higher and the quenched fraction is significantly lower at fixed mass. The cosmosTNG suite will be a valuable tool for studying galaxy formation at cosmic noon and interpreting observations from HST, JWST, and other large multi-wavelength surveys of the COSMOS field.