A&A 475, 109-114 (2007)
DOI: 10.1051/0004-6361:20077333

Cosmological hydrogen recombination: Lyn line feedback and continuum escape

J. Chluba¹ and R. A. Sunyaev<sup>1, 2

1</sup>  Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching bei München, Germany
    e-mail: jchluba@mpa-garching.mpg.de
²  Space Research Institute, Russian Academy of Sciences, Profsoyuznaya 84/32, 117997 Moscow, Russia

(Received 20 February 2007 / Accepted 16 September 2007 )

Abstract
We compute the corrections to the cosmological hydrogen recombination history due to delayed feedback of Lyman-series photons and the escape in the Lyman-continuum. The former process is expected to slightly delay recombination, while the latter should allow the medium to recombine a bit faster. It is shown that the subsequent feedback of released Lyman-n photons on the lower lying Lyman-(n-1) transitions yields a maximal correction of at . Including only Lyman- feedback onto the Lyman- transition, accounts for most of the effect. We find corrections to the cosmic microwave background TT and EE power spectra with typical peak to peak amplitude and at . The escape in the Lyman-continuum and feedback of Lyman- photons on the photoionization rate of the second shell lead to modifications of the ionization history which are very small (less than ).

Key words: cosmic microwave background -- cosmology: miscellaneous

© ESO 2007