Leveraging Early Public JWST Data to Measure Luminosity Functions and Rest-UV Slopes from 6

The evolution of the rest-frame ultraviolet (UV) luminosity function encodes information on the key physical properties regulating galaxy evolution. While theoretical models, invoking a variety of sub-grid models, are able to match observations at z < 8, their predictions have significant scatter at higher redshifts. This is understandable at z > 9, Hubble only probes galaxies with a single imaging filter, so there is a variety of tension between observational studies. This will change with Webb; Deep near-infrared imaging planned early in Cycle 1 will probe 1-5um, allowing the selection of large samples of robust z~10 galaxies. We propose for archival funding to analyze the data from four publicly available datasets (two Early Release Science programs, and two Guaranteed Time Observer programs with public releases). We will analyze these data in a systematic way to select robust samples of galaxies in this epoch, to 1) measure the shape of the bright end of the rest-UV luminosity function, constraining models of star-formation efficiencies, and 2) measure robust rest-UV colors, placing limits on the chemical enrichment in early galaxies. Doing these analyses early in the Webb mission will allow our first glimpse into the physical processes dominating galaxy evolution in the first 500 Myr, setting the stage for future Cycle 2 programs to push farther into the early universe.