Rapid HeII->HeI recombination and radiation concerned with this process

E. E. Kholupenko; A. V. Ivanchik; D. A. Varshalovich

doi:10.1111/j.1745-3933.2007.00316.x

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arXiv · astro-ph/0703438

Rapid HeII->HeI recombination and radiation concerned with this process

E. E. Kholupenko·A. V. Ivanchik·D. A. Varshalovich

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Abstract

Recombination of the primordial helium plasma (HeII->HeI, $z \simeq 1500 - 3000$) is considered. This process has an effect on the CMBR anisotropy and CMBR spectrum distortion. In this work an influence of neutral hydrogen on kinetics of HeII->HeI recombination is investigated in the frame of the standard cosmological model. It is shown that small amount of neutral hydrogen ($10^{-5} - 10^{-2}$ of total number of hydrogen ions and atoms) leads to acceleration of HeII->HeI recombination at $z\lesssim 2000$ and at $z\lesssim 1600$ quasi-equilibrium HeII->HeI recombination (according to the Saha formula) becomes valid.

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E. E. Kholupenko, A. V. Ivanchik, D. A. Varshalovich. 2007-03-16. Rapid HeII->HeI recombination and radiation concerned with this process. https://doi.org/10.1111/j.1745-3933.2007.00316.x

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