darkhistory.physics.xe_Saha

darkhistory.physics.xe_Saha(rs, species)

Saha equilibrium ionization value for H and He.

Parameters:

rsfloat

The redshift in 1+z.

species{‘HI’, ‘HeI’}

The relevant species.

Returns:

float

The Saha equilibrium xe.

Notes

See astro-ph/9909275 and 1011.3758 for details.