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Register a new userKinematic Sunyaev-Zeldovich Cosmic Microwave Background Temperature Anisotropies Generated by Gas in Cosmic Structures
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Added by
Fernando Atrio-Barandela
Publication date
2008
fields
Physics
and research's language is
English
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If the gas in filaments and halos shares the same velocity field than the luminous matter, it will generate measurable temperature anisotropies due to the Kinematic Sunyaev-Zeldovich effect. We compute the distribution function of the KSZ signal produced by a typical filament and show it is highly non-gaussian. The combined contribution of the Thermal and Kinematic SZ effects of a filament of size $Lsimeq 5$Mpc and electron density $n_esimeq 10^3m^{-3}$ could explain the cold spots of $deltasim -200mu$K on scales of 30 found in the Corona Borealis Supercluster by the VSA experiment. PLANCK, with its large resolution and frequency coverage, could provide the first evidence of the existence of filaments in this region. The KSZ contribution of the network of filaments and halo structures to the radiation power spectrum peaks around $lsim 400$, a scale very different from that of clusters of galaxies, with a maximum amplitude $l(l+1)C_l/2pisim 10-25 (mu K)^2$, depending on model parameters, i.e., $sigma_8$ and the Jeans length. About 80% of the signal comes from filaments with redshift $zle 0.1$. Adding this component to the intrinsic Cosmic Microwave Background temperature anisotropies of the concordance model improves the fit to WMAP 3yr data by $Deltachi^2simeq 1$. The improvement is not statistically significant but a more systematic study could demonstrate that gas could significantly contribute to the anisotropies measured by WMAP.
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