Reionization on Large Scales I: A Parametric Model Constructed from Radiation-Hydrodynamic Simulations

Understand

We present a new method for modeling inhomogeneous cosmic reionization on large scales.

• Utilizing high-resolution radiation-hydrodynamic simulations with 2048^3 dark matter particles, 2048^3 gas cells, and 17 billion adaptive rays in a L = 100 Mpc/h box, we show that the density and reionization-redshift fields are highly correlated on large scales (>~ 1 Mpc/h).
• This correlation can be statistically represented by a scale-dependent linear bias.
• We construct a parametric function for the bias, which is then used to filter any large-scale density field to derive the corresponding spatially varying reionization-redshift field.