Cosmic Sands: The Origin of Dusty, Star-forming Galaxies in the Epoch of Reionization

Understand

We present the Cosmic Sands suite of cosmological zoom-in simulations based on the Simba galaxy formation model in order to study the build up of the first massive and dusty galaxies in the early Universe.

• Residing in the most massive halos, we find that the compact proto-massive galaxies undergo nearly continuous mergers with smaller subhalos, boosting star formation rates (SFRs) and the build up of stellar mass.
• The galaxies are already appreciably chemically evolved by z=10, with modeled dust masses comparable to those inferred from observations in the same epoch.
• We track gas accretion onto the galaxies to understand how extreme SFRs can be sustained by these early systems.