Extended Photometry for the DEEP2 Galaxy Redshift Survey: A Testbed for Photometric Redshift Experiments

TL;DR

This paper presents a new, calibrated photometric catalog combining DEEP2, CFHTLS, and SDSS data, providing a valuable resource for testing and improving photometric redshift algorithms for large surveys.

Contribution

The authors created a comprehensive, uniformly calibrated photometric catalog with spectroscopic redshifts, enhancing the DEEP2 dataset for future photo-z research and survey planning.

Findings

Catalog contains ~27,000 objects with ugriz photometry and spectroscopic redshifts.

Improved photometry calibration and astrometry for better redshift predictions.

The dataset serves as a testbed for future photometric redshift algorithms.

Abstract

This paper describes a new catalog that supplements the existing DEEP2 Galaxy Redshift Survey photometric and spectroscopic catalogs with ugriz photometry from two other surveys; the Canada-France-Hawaii Legacy Survey (CFHTLS) and the Sloan Digital Sky Survey (SDSS). Each catalog is cross-matched by position on the sky in order to assign ugriz photometry to objects in the DEEP2 catalogs. We have recalibrated the CFHTLS photometry where it overlaps DEEP2 in order to provide a more uniform dataset. We have also used this improved photometry to predict DEEP2 BRI photometry in regions where only poorer measurements were available previously. In addition, we have included improved astrometry tied to SDSS rather than USNO-A2.0 for all DEEP2 objects. In total this catalog contains ~27,000 objects with full ugriz photometry as well as robust spectroscopic redshift measurements, 64% of which have r > 23. By combining the secure and accurate redshifts of the DEEP2 Galaxy Redshift Survey with ugriz photometry, we have created a catalog that can be used as an excellent testbed for future photo-z studies, including tests of algorithms for surveys such as LSST and DES.