Matched-filter analysis of large scale structures in the 1st CfA slice using an anisotropic wavelet basis

A method of analysis of 2D images using a generalized anisotropic wavelet basis, which includes the isotropic wavelet also, is discussed. Use of an elliptical “Mexican Hat” wavelet as a matched-filter is shown to detect and characterize elongated features at higher significance level and more detail compared to the use of an isotropic wavelet only. The method is particularly suited for study of large scale structure which consists of highly anisotropic filaments as well as nearly isotropic voids. The method has been applied to the data from the first slice of the CfA survey. For structures and voids in the CfA slice, we obtain their sizes, major-to-minor axis ratios, orientations and also their level of significance.