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2.3 Building the extended PSF

Deriving the extended PSF of an image is very important in many aspects of the analysis of the objects within it. Gnuastro has a set of installed scripts, designed to simplify the process following the recipe of Infante-Sainz et al. (2020, https://arxiv.org/abs/1911.01430); for more, see PSF construction and subtraction. An overview of the process is given in Overview of the PSF scripts.

• Preparing input for extended PSF
• Saturated pixels and Segment’s clumps
• One object for the whole detection
• Building outer part of PSF
• Inner part of the PSF
• Uniting the different PSF components
• Subtracting the PSF