Sphenix: Smoothed Particle Hydrodynamics for the next generation of galaxy formation simulations

Understand

Smoothed Particle Hydrodynamics (SPH) is a ubiquitous numerical method for solving the fluid equations, and is prized for its conservation properties, natural adaptivity, and simplicity.

• We introduce the Sphenix SPH scheme, which was designed with three key goals in mind: to work well with sub-grid physics modules that inject energy, be highly computationally efficient (both in terms of compute and memory), and to be Lagrangian.
• Sphenix uses a Density-Energy equation of motion, along with variable artificial viscosity and conduction, including limiters designed to work with common sub-grid models of galaxy formation.
• In particular, we present and test a novel limiter that prevents conduction across shocks, preventing spurious radiative losses in feedback events.