darkhistory.physics.photo_ion_rate

darkhistory.physics.photo_ion_rate(rs, eng, xH, xe, atom=None)

Photoionization rate in cm^-3 s^-1.

Parameters:

rsfloat

Redshift (1+z).

engndarray

Energies to evaluate the cross section.

xHfloat

Ionization fraction nH+/nH.

xefloat

Ionization fraction ne/nH = nH+/nH + nHe+/nH.

atom{None,’HI’,’HeI’,’HeII’}, optional

Determines which photoionization rate is returned. The default value is None, which returns the total rate.

Returns:

float

The photoionization rate of the particular species or the total ionization rate.