Clustering of High Redshift Galaxies in the Canada-France Deep Fields Survey and Virmos Deep Imaging Survey

Abstract

The Canada-France Deep Fields (CFDF) and the VIRMOS Deep Imaging Survey (VDIS) are deep, wide angle, multi-colour imaging surveys. The CFDF covers ∼0.65 deg2 in U BV I and reaches a limiting magnitude of U AB(3σ, 3″)∼27.5. The VDIS deep field covers∼1.2 deg2 in BV RI and reaches a limiting magnitude of B AB(3σ, 3″) ∼ 26.5. With these data, we are able to identify some of the largest samples of photometrically selected Lyman-break galaxies (LBGs) at z∼3 to a limiting magnitude of I AB(3σ, 3″)∼24.5 and at z∼4 to a limiting magnitude of I AB(3σ, 3″)∼24. We select 1294 z∼3 LBGs for 20<I AB<24.5, and 194 z∼4 LBGs for 20<I AB<24. We determine the correlation length in comoving space, r 0 and, using Cold Dark Matter (CDM) models, we estimate a linear bias, b, for LBGs. For Λ-flat cosmological parameters, we measure r 0=(5.9±0.5)h −1 Mpc and b=3.5±0.3 at z∼3 and r 0=(7.4±1.2)h −1 Mpc and b=5.4±0.8 at z∼4. Although, the CFDF data indicates in one field (at a 3σ level) that r 0 depends on sample limiting magnitude: brighter LBGs are more clustered than fainter ones. The strong clustering and the large bias of high-redshift LBGs are consistent with models of biased galaxy formation and show that they are associated with massive CDM halos.