Cosmological Radiative Transfer

We’ve seen so far that you can initialize stellar and BH populations and radiation backgrounds independently, i.e., without doing a full blown 21-cm calculation. However, the radiation background will in general modify the properties of the intergalactic medium, which will then influence the subsequent evolution of the radiation background (and so on). Coupling radiation from stars and BHs to the IGM requires use of the ares.solvers.IntergalacticMedium module:

import ares

igm = ares.solvers.IGM()

# Optical depth between 10 <= z <= 12 at 500 eV.
# By default, assumes IGM is neutral
tau_neutral = igm.OpticalDepth(10, 12, 500)

# Can supply ionized fraction as constant
tau_xconst = igm.OpticalDepth(10, 12, 500, xavg=0.5)