Null tests performed on difference maps, free of any foreground and cosmological signal. (a) represents the kurtosis of the SMHW coefficients, as a function of the scale , for the map, that is, for a map built as the difference of the difference assemblies observations at 41 GHz. (b) is as the previous one, but for the difference map, that is, at 61 GHz. Finally, (c) provides the variation of the SMHW coefficients as a function of the wavelet scale, but for the difference map obtained with the 4 difference assemblies of WMAP at 90 GHz, that is, . The blue asterisks represent values for the data whereas red, green and magenta regions represented the acceptance intervals at 32%, 5%, and 1%, respectively, determined by simulations.
