CHEF bases for astronomical data analysis

I will introduce a new approach to model the light distribution of galaxies, an orthonormal polar basis called CHEFs, constructed using Chebyshev rational functions and Fourier series. This basis displays remarkable flexibility, being able to accurately fit all kind of galaxy shapes, including irregular, spiral, elliptical, highly compact, and highly elongated galaxies with much more accuracy than other widely-used methods, such as GALFIT or the shapelet bases. The CHEF bases have been successfully applied to many different astronomical areas and I will show some applications I have already developed: performance with large and well resolved data, photometric and shear measurements for weak lensing, color determination without PSF-matching, removal of the brightest galaxies in clusters and, especially, measurement of the IntraCluster Light (ICL). For this latter application we have desenvolved an extremely accurate method that does not impose any artificial thresholds and avoids the ambiguity introduced by free parameters that are usually set in the ICL measurement. I will show the main results obtained from the analysis of several galaxy clusters observed by the CLASH project and the Frontier Fields program.