We describe the algorithm used to select the Luminous Red Galaxy (LRG) sample for the extended Baryon Oscillation Spectroscopic Survey (eBOSS) of the Sloan Digital Sky Survey IV (SDSS-IV) using photometric data from both the SDSS and the Wide-Field Infrared Survey Explorer (WISE). LRG targets are required to meet a set of color selection criteria and have z-band and i-band MODEL magnitudes z < 19.95 and 19.9 < i < 21.8, respectively. Our algorithm selects roughly 50 LRG targets per square degree, the great majority of which lie in the redshift range 0.6 < z < 1.0 (median redshift 0.71). We demonstrate that our methods are highly effective at eliminating stellar contamination and lower-redshift galaxies. We perform a number of tests using spectroscopic data from SDSS-III/BOSS to determine the redshift reliability of our target selection and its ability to meet the science requirements of eBOSS. The SDSS spectra are of high enough signal-to-noise ratio that at least 89% of the target sample yields secure redshift measurements. We also present tests of the uniformity and homogeneity of the sample, demonstrating that it should be clean enough for studies of the large-scale structure of the universe at higher redshifts than SDSS-III/BOSS LRGs reached.
@article{arxiv.1508.04478,
title = {The SDSS-IV extended Baryonic Oscillation Spectroscopic Survey: Luminous Red Galaxy Target Selection},
author = {Abhishek Prakash and Timothy C. Licquia and Jeffrey A. Newman and Ashley J. Ross and Adam D. Myers and Kyle S. Dawson and Jean-Paul Kneib and Will J. Percival and Julian E. Bautista and Johan Comparat and Jeremy L. Tinker and David J. Schlegel and Rita Tojeiro and Shirley Ho and Dustin Lang and Sandhya M. Rao and Cameron K. McBride and Guangtun Ben Zhu and Joel R. Brownstein and Stephen Bailey and Adam S. Bolton and Timothee Delubac and Vivek Mariappan and Michael R. Blanton and Beth Reid and Donald P. Schneider and Hee-Jong Seo and Aurelio Carnero Rosell and Francisco Prada},
journal= {arXiv preprint arXiv:1508.04478},
year = {2016}
}