CheFlet polar basis for astronomical data analysis

We present a new method to decompose galaxy images. We have developed a polar orthonormal basis, built using Chebyshev rational functions to expand the radial coordinate, and Fourier series to represent the azimuthal component. The method can fit galaxies in a very compact way, including simultaneously most of the galaxy substructure and the extended wings of the galaxy profile. Some applications of this method are being developed: photometry measurements, shape characterization for lensing purposes and clusters processing. All these concepts will be introduced in a very simple and visual way.