Galaxies associated with z ∼ 4 damped Lyα systems. I. Imaging and photometric selection

This paper describes the acquisition and analysis of imaging data for the identification of galaxies associated with z ∼ 4 damped Lyα systems. We present deep BRI images of three fields known to contain four z ∼ 4 damped systems. We discuss the reduction and calibration of the data, detail the color criteria used to identify z ∼ 4 galaxies, and present a photometric redshift analysis to complement the color selection. We have found no galaxy candidates closer to the QSO than 7″ that could be responsible for the damped Lyα systems. Assuming that at least one of the galaxies is not directly beneath the QSO, we set an upper limit on this damped Lyα system of L < L_LBG*/4. Finally, we have established a Web site to release these imaging data to the public.