I have some notes about why I made some changes. They are [here](https://github.com/Christopher-Bradshaw/DECALS_selection) but this is a private repo. Let me know if you want them.
The DESI Legacy Imaging Surveys have delivered deep grz optical imaging and unWISE W1 and W2 mid-infrared imaging of over 20,000 sq. deg of the extragalactic sky.
This repository contains code and papers for a multi-pronged analysis of the group- and cluster-scale dark matter halos identified in Legacy Survey imaging, particularly the stellar mass content of the central galaxies.
The key science goals are to:
- Obtain an accurate census of the integrated stellar masses of massive central galaxies---which dominate the massive end of the galaxy stellar mass function---as a function of halo mass and redshift.
- Measure the stellar mass density profiles and structural properties (e.g., half-mass radius, concentration), and their correlation with dark matter halo assembly histories.
- Measure the stellar mass-halo mass relation and the scatter in the stellar masses of central galaxies, as a probe of star formation efficiency and feedback in massive systems.
- Measure the fraction of stars formed in situ versus ex situ in massive spheroidal galaxies.
- And much more...!
We gratefully acknowledge funding support for this work from the National Science Foundation under grant AST-1616414 and the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award Number DE-SC002008.
