Publication : t09/244

The y-sky: diffuse spectral distortions of the cosmic microwave background

Pitrou C. (Institute of Cosmology & Gravitation, University of Portsmouth, Portsmouth PO1 2EG, England UNITED KINGDOM (UK))
Bernardeau F. (CEA, IPhT (Institut de Physique Théorique), F-91191 Gif-sur-Yvette, France)
Uzan J.-P. (Department of Mathematics and Applied Mathematics, University of Cape Town, Rondebosh 7701, Cape Town)
The non-linear evolution of the energy density of the radiation is shown to induce spectral distortions of the cosmic microwave background both at recombination and during the reionization era. This distortion has the same spectral signature as the one produced by the re-scattering of photons by non-relativistic hot electrons, the thermal Sunyaev-Zeldovich effect, whose amplitude is quantified by a Compton y parameter. A diffuse y-sky is then expected to emerge from mode couplings in the non-linear evolution of the cosmological perturbations and to superimpose to the point source contributions of galaxy clusters. The equations describing the evolution of the y field and a hierarchy governing its angular multipoles are derived from the second order Boltzmann equation. These equations are then integrated numerically to obtain the first predicted power spectrum of the diffuse y-sky. It is found to be a remarkable tracer of the reionization history of the Universe.
Année de publication : 2010
Revue : JCAP 1007 019 (2010)
DOI : 10.1088/1475-7516/2010/07/019
Preprint : arXiv:0912.3655
Langue : Anglais

Fichier(s) à télécharger :
  • 1475-7516_2010_07_019.pdf
  • publi.pdf


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