Modeling turbulent galaxy formation

University Of Chicago, Chicago IL

Investigators

Abstract

Cosmic gas flows accompanying galaxy formation have high velocities, span enormous scales, and are highly turbulent, but the effects of turbulence on galaxy formation and associated processes are still largely unexplored. This project is a systematic exploration of turbulence and its effects on the observable properties of galaxies using self-consistent and realistic high-resolution cosmological simulations. It will address several fundamental issues in the interpretation of observations of galaxies across cosmic time. The Adler Planetarium will use high-fidelity, scientifically-accurate visualizations of the planned simulations suitable for full-dome projectors. These visualizations will be available to other planetaria, and for online streaming and viewing with the increasingly widespread virtual reality headsets, which can provide a new and effective way to reach broad segments of society, including students and educators, showing the results of cutting-edge research in an engaging and easily accessible form. The work is enabled by a recent implementation of subgrid turbulence by this team, and will (1) investigate whether slip sheet instabilities develop in cold gas accretion flows, and the effect of turbulence on key properties; (2) explore gravitational instability and stellar feedback in driving turbulence; (3) quantify how turbulence affects the density structure of gas, pressure support, star formation, and mixing processes; and (4) explore models of the initial mass function (IMF) of stars. The methods use a model of efficient and multi-faceted feedback, including feedback due to cosmic rays, formation of molecular hydrogen, chemical enrichment and evolution, and radiative transfer of ionizing and far-ultra-violet radiation. The study explores key issues, including the processes controlling gas supply to galaxies, the environmental dependence of star and star cluster formation efficiency, and the IMF in galaxies of different stellar masses, metallicities, morphologies, and star formation histories. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.