Initial studies of photometric redshifts with ComCam from DP1

Abstract

This technote holds reports based on the first analyses of the Data Preview 1 (DP1) ComCam data by the Science Unit for photometric redshifts. Although photometric redshifts are not a official DP1 data product, the “Photo-z Science Unit” generated photo-z estimates for every galaxy in DP1 using the available multi-band imaging on a best-effort basis. This work included developing training and test datasets by matching DP1 data to high-quality reference redshifts obtained with spectroscopy, Grism data, and multi-band photometry. The Science Unit used the RAIL software package to make photometric redshift estimates using eight different algorithms, developed simple scientific performance metrics, used those metrics to explore how the performance of the algorithms varied with configuration changes, derived more optimized configurations of the algorithms and tested the performance of those configurations. This work, the resulting data products and expected data distribution mechanism are all described there.