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1) find ATLAS magnitudes of isolated SDSS LRG galaxies and construct photo-z estimator (like redmapper) for these objects.
2) Make star-galaxy discriminator perhaps by including WISE data?
3) extract photometry and morphology from stacked images 4)images, perhaps add WISE or GAIA data to get another color?
4) make color-magnitude diagram of plausible cluster members and look for LRG finger.
5) run on entire e-Rosita Xray cluster catalog, for example https://www.aanda.org/articles/aa/full_html/2022/05/aa41120-21/aa41120-21.html