Mapping the large-angle deviation from Gaussianity in simulated CMB maps

The detection of the type and level of primordial non-Gaussianity in the CMB data is essential to probe the physics of the early universe. Since one does not expect that a single statistical estimator can be sensitive to all possible forms of non-Gaussianity which may be present in the data, it is important to employ different statistical indicators to study non-Gaussianity of CMB. In recent works we have proposed two new large-angle non-Gaussianity indicators based on skewness and kurtosis of patches of CMB sky sphere, and used them to find significant deviations from Gaussianity in frequency bands and foreground-reduced CMB maps. An outcome of the analysis is that the level of non-Gaussianity of the ILC7 yr map is higher than that of the simulated maps for f[suplocal][subNL] within WMAP bounds. This provides quantitative indications on the suitability of the ILC7 yr map as Gaussian reconstruction of the full-sky CMB.