The impact and response of minihalos and the inter-halo medium on cosmic reionization

Understand

An ionization front (I-front) that propagates through an inhomogeneous medium is slowed down by self-shielding and recombinations.

• We perform cosmological radiation hydrodynamics simulations of the I-front propagation during the epoch of cosmic reionization.
• The simulations resolve gas in minihalos (halo mass $10^4\lesssim M_h[{\rm M}_\odot]\lesssim 10^8)$ that could dominate recombinations, in a computational volume that is large enough to sample the abundance of such halos.
• The numerical resolution is sufficient (gas particle mass $\sim 20{\rm M}_\odot$, spatial resolution $< 0.1\;{\rm ckpc}$) to allow accurate modelling of the hydrodynamic response of gas to photo-heating.