Simulating galaxy clusters (and their galaxies!) with IllustrisTNG

May 21, 2018 - 11:00 am to 12:00 pm

Campus, Varian 355

Annalisa Pillepich (Max Planck Institute for Astronomy)

The IllustrisTNG simulations ( are a novel laboratory to explore galaxy physics and to quantify the assembly and evolution of galaxy populations across an unprecedented range of halo masses, environments, evolutionary stages and cosmic times. IllustrisTNG is an ongoing program of large cosmological volume simulations where gravity, magnetohydrodynamics, and prescriptions for star formation, stellar evolution, metal enrichment, gas cooling/heating, galactic outflows and black-hole feedback are all taken into account within the LCDM cosmology. In the talk, I will focus on the new synthetic dataset of hundreds of massive galaxy clusters produced with IllustrisTNG. I will showcase what we are learning about their stellar mass assembly and stellar mass distribution, the quenching of their central galaxies and families of satellites, and the influence of the  central super massive black holes on the thermodynamical properties of the gas within and around the galaxies. For example, the TNG model naturally returns continuous gradients in the cool core vs. non cool core criteria and overall reasonable consistency with observational findings of cool core fractions at intermediate z. Quenched massive galaxies have systematically higher circumgalactic entropies, at fixed mass, than their star forming counterparts. The effects of black hole feedback produce a bending towards the group-mass scale of the X-ray scaling relations. And finally, future X-ray absorption spectroscopy campaigns have the potential to powerfully constrain models via the measurement of the column densities and spatial distribution of the OVII and OVIII ions that we predict to dominate in the circus galactic medium around the most massive galaxies.