Contributed Talk - Splinter Computation

Thursday, 24 September 2020, 09:02   (virtual room B)

Pushing to cosmological zoom simulations to new limits: exquisitely resolved galactic dynamics

Robert John James Grand
Max Planck Institute for Astrophysics

Cosmological simulations that successfully simulate the formation of Milky Way-mass spiral galaxies have shown dramatic progress in recent years, and are incredibly useful tools used for the interpretation of observations. With recent and future large observational surveys raising the bar in terms of accuracy, detail and shear size, simulations require ever-higher resolution to interpret new physical phenomena revealed by observations, in addition to unlocking deeper theoretical studies of galaxy formation and dynamics, all while maintaining the correct cosmological environment. I will discuss our ongoing intense computational efforts to meet this challenge and present the highest resolution cosmological simulations of Milky Way galaxies to date, achieving more than 1e8 particles in the disc (particle mass < 1e3 solar masses), and capturing high-fidelity gas and stellar dynamics in a full Lambda Cold Dark Matter cosmology. These extremely challenging simulations push the limits of what is currently possible, costing of the order 10-20M CPU hours and run on thousands of cores. I will demonstrate that our galaxy formation model is extremely numerically well-converged across 5 orders of magnitude in resolution, and present new results concerning several important aspects of galaxy formation, such as the formation of detailed galactic structures like galactic spiral arms and stellar streams, and the origin of High Velocity clouds and ultra-faint galaxies that surround the Galaxy.