Speaker
Description
We present a new analysis of the IllustrisTNG galaxy formation model based on a set of simultaneous multi-zoom hydrodynamical simulations of halos embedded within a common cosmological volume. This framework allows us to efficiently probe galaxy populations across a wide range of masses and environments while maintaining full cosmological context. We compare predictions for the galaxy stellar mass function and gas fractions in groups and clusters to current observational measurements, using Gaussian-process emulation to explore model variations at low computational cost. Our results quantify where IllustrisTNG provides a robust description of galaxy populations and identify regimes in which tensions with the data reveal limitations of the model-assumptions.