Baryonification and Ramses: Simulating the Universe the Easy Way

Abstract

Cosmological structure formation is dominated by an invisible, collisionless substance called dark matter, with a large subdominant component of baryons. Whereas dark matter only interacts gravitationally, baryons are affected by collisional, magnetic, nuclear, and relativistic processes. This makes full DM+baryon simulations exceedingly computationally expensive compared to Dark Matter Only (DMO) simulations. To fully understand structure formation without running such expensive simulations, baryonification codes are employed, modifying the output of DMO simulations to emulate baryonic effects. We present the results of a baryonification pipeline on a pair of mini-Ramses simulations, including implications for mock SZ Effect maps. We conclude, in agreement with literature, that baryonification codes are both necessary and sufficient for emulating the quantitative differences between dark matter and baryons, and comprise a promising new direction for computational cosmology.