ASTROPHYSICS

The formation of the first galaxies marked the end of the cosmological dark ages. Radiation from the first stars ionized and heated inter-galactic gas. As these ionized gas bubbles grew and percolated, the whole Universe was transformed from a dark, cold, neutral state into a hot ionized one, about a billion years after the Big Bang. The SPHINX cosmological radiation-hydrodynamics simulations of the first billion years are designed to understand the formation of the first galaxies and how they contributed to reionization via the interplay of star formation, stellar radiation, and powerful supernova explosions that disrupt galaxies and allow their radiation to escape into inter-galactic space.