The Mexican Hat Wavelet Family. Application to the study of non-Gaussianity in cosmic microwave background maps

The detection of the non-Gaussian signal due to extragalactic point sources and its separation from the possible intrinsic non-Gaussianity is an issue of great importance in the cosmic microwave background (CMB) analysis. The Mexican Hat Wavelet Family (MHWF), which has been proved very useful for the detection of extragalactic point sources, is applied here to the study of non-Gaussianity due to point sources in CMB maps. We carry out simulations of CMB maps with the characteristics of the forthcoming Planck mission at 70 and 100 GHz and filter them with the MHWF. By comparing the skewness and kurtosis of simulated maps with and without point sources, we are able to detect clearly the non Gaussian signal due to point sources for flux cuts as low as 0.4 Jy (70 GHz) and 0.3 Jy (100 GHz). The MHWF performs better in this respect than the Mexican Hat Wavelet and much better than the Daubechies 4 wavelet.