Survey Overview

Upcoming missions such as Euclid, LSST and WFIRST will rely on well-calibrated photometric redshift estimates for the billions of galaxies they will detect. As described in Masters, Capak, Stern et al. 2015, a nearly-optimal method to calibrate redshifts is to map the empirical color distribution of galaxies, then obtain targeted redshifts in under-sampled regions of color space. The C3R2 survey is a joint effort between Caltech (PI: J. Cohen), NASA (PI: D. Stern), the University of California (PI: B. Mobasher), and the University of Hawaii (PI: D. Sanders), with European participation with the GTC and VLT (PI: F. Castander), to perform this mapping to the Euclid depth. The first five nights of observing were allocated by Caltech in the 2016A semester, all with Keck. Significant subsequent allocations have been made, totaling >30 Keck nights and ~200 hours of VLT time. See Masters et al. 2017 for more survey details. Redshifts from 2016A can be found here.