Estimating power spectrum of Sunyaev-Zeldovich effect from the cross-correlation between the Wilkinson microwave anistropy probe and the two micron all sky survey

We estimate the power spectrum of the Sunyaev-Zel'dovich (SZ) effect-induced temperature fluctuations on sub-degree scales by using the cross-correlation between the three-year WMAP maps and the 2MASS galaxy distribution. We produced the SZ effect maps by hydrodynamic simulation samples of the ACDM model and show that the SZ effect temperature fluctuations are highly non-Gaussian. The PDF of the temperature fluctuations has a long tail. More than 70% of the power of the SZ effect temperature fluctuations is attributed to the top similar to 1% wavelet modes (long-tail events). On the other hand, the CMB temperature fluctuations basically are Gaussian. Although the mean power of CMB temperature fluctuations on subdegree scales is much higher than that of the SZ effect map, the SZ effect temperature fluctuations on subdegree scales is much higher than that of the SZ effect map, the SZ effect temperature fluctuations associated with top 2MASS clusters is comparable to the power of CMB temperature fluctuations on the same scales. Thus, from noisy WMAP maps, once can have a proper estimation of the SZ effect power at the positions of the top 2MASS clusters. The power spectrum given by these top wavelet modes is useful for constraining the density fluctuation amplitude parameter sigma(8). We find that the power spectrum of these top wavelet modes of the SZ effect on subdegree scales basically is consistent with the simulation maps produced with sigma(8) = 0.84. The simulation samples of sigma(8) = 0.74 show, however, significant deviation from the detected SZ power spectrum. This value can be ruled out with a 99% confidence levelif all other cosmological parameters are teh same as that given by the three-year WMAP results.