The importance of the extended point spread function in low surface brightness science

The low surface brightness universe remains as one of the fields in astrophysics that has not been explored in deep so far, due to the intrinsic difficult in observing and analysing the data. Specially relevant is the effect of the point spread function (PSF). While the PSF is modeled and used in almost all surveys, they are always of the size of a few arcoseconds in radius. However, it is known that the effect of the PSF extends much more far away than just a few arcoseconds. Therefore, it is crucial to have the tools and methodology to be able to construct PSFs as extended as possible. In this context, Infante-Sainz et al. 2020 used the Sloan Digital Sky Survey (SDSS) images for creating the extended PSFs of that survey (in five filters: u, g, r, i, and z). This work is entirely reproducible and all the PSFs obtained are publicly available. In this dissertation we will go through this work in order to see how extended PSFs can be obtained and used for correcting the scattered light of very bright stars.