HeII->HeI Recombination of Primordial Helium Plasma Including the Effect of Neutral Hydrogen

Understand

The HeII->HeI recombination of primordial helium plasma (z = 1500 - 3000) is considered in terms of the standard cosmological model.

• This process affects the formation of cosmic microwave background anisotropy and spectral distortions.
• We investigate the effect of neutral hydrogen on the HeII->HeI recombination kinetics with partial and complete redistributions of radiation in frequency in the HeI resonance lines.
• It is shown that to properly compute the HeII->HeI recombination kinetics, one should take into account not only the wings in the absorption and emission profiles of the HeI resonance lines, but also the mechanism of the redistribution of resonance photons in frequency.