Spectroscopic Calibration of uBVRI Photometric Selection

We present a survey for z ∼ 3 Lyman break galaxies (LBGs) associated with damped Lyman α systems (DLAs) with the primary purpose of determining the DLA-LBG cross-correlation. This paper describes the acquisition and analysis of imaging and spectroscopic data of 9 quasar fields having 11 known z ∼ 3 DLAs covering an area of 465 arcmin. Using deep uBVRI images, 796 LBG candidates to an apparent RAB magnitude of 25.5 were photometrically selected from 17,343 sources detected in the field. Spectroscopic observations of 529 LBG candidates Visiting Astronomer, W. M. Keck Telescope. The Keck Observatory is a joint facility of the University of California, the California Institute of Technology, and NASA and was made possible by the generous financial support of the W. M. Keck Foundation. Department of Physics and Center for Astrophysics and Space Sciences, University of California, San Diego, 9500 Gilman Drive, Code 0424, La Jolla, CA 92093-0424. University of California Observatories, Lick Observatory, Natural Sciences II Annex, UC Santa Cruz, Santa Cruz CA 95064. NSF Postdoctoral Fellow, Yale University, P.O. Box 208101, New Haven, CT 06520. Andes Prize Fellow, Universidad de Chile, Casilla 36-D, Santiago, Chile.