2004ApJ...609..513B

We present our results on the cross-correlation of Lyman break galaxies (LBGs) around three damped Lyα absorbers (DLAs) at z_abs≃3 from deep [µ_I,AB(sky)≃27.6 mag/arcsec2] UBVI KPNO 4 m/MOSAIC images. The large area of the MOSAIC images, 0.31 deg² or ∼65x65 h^–1₇₁Mpc comoving at redshift z=3, allows us to probe the clustering of LBGs on scales up to 20 Mpc comoving. Our survey covers a total of 1 deg² and contains ∼3000 LBGs with photometric redshifts between 2.8 and 3.5. Using the redshift likelihood distributions with m_Ias a prior, we selected LBGs within a redshift slice of width W_z=0.15 (corresponding to σ_z_, the uncertainty in photometric redshifts) centered on the redshift of the absorbers. Within that redshift slice, we find that the DLA-LBG cross-correlation w_dgis w_dg=(1.62±1.32)xw_gg, where w_ggis the LBG autocorrelation. This corresponds to a correlation length of r₀=5±4.5 h^–1 (comoving) (or r₀=7±6.8 h^–1₇₁Mpc). The cross-correlation is most significant on scales 5-10 Mpc. Through Monte Carlo simulations, we find that w_dgis significantly greater than zero at the greater than 95% level. In three other redshift slices that do not contain a DLA, we do not find any evidence of clustering. A larger sample will enable us to discriminate between w_dg/w_gg<1 and w_dg/w_gg>1, i.e., to test whether DLA halos are more or less massive than LBG halos.