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## Input Catalog   To make sure that the fake galaxies we inject on the images are as realistic as possible, we choose to use the models of COSMOS galaxies from Lackner (20??). The catalog is based on Exponential (Exp), De Vaucouleurs (Dev), and single Sersic component (Sersic) fitting of galaxies with $I_{F814W} $$I_{F814W}  \le 23.5\ mag$ mag$$  on the ACS high-resolution images. From the full COSMOS catalog, we select appropriate Exp, Dev, and Sersic models according to the following standards: