Structure Formation and Galaxy Evolution at Z=3–7 Probed by 2,600 Galaxies in The Subaru Deep Fields

Abstract

We investigate photometric and clustering properties of galaxies at z=3.5–5.2 based on large samples of 2,600 Lyman Break Galaxies (LBGs) and Lyman α Emitters (LAEs) detected in deep (i′∼27) and wide-field (1,200 arcmin²) images taken in the Subaru Deep Field (SDF) and the Subaru/XMM Deep Field (SXDF). We find in the luminosity functions of LBGs that the number density of bright galaxies (M ₁₇₀₀<−22; corresponding to SFR _corr>100M⊙yr⁻¹) decreases significantly from z=4 to 5. We investigate the evolution of UV-luminosity density at 1700A, ρ _UV, and find that ρ _UV does not significantly change from z=3 to z=5, i.e., ρ _UV(z=4)/ρ _UV(z=3)=1.0±0.2 and ρ _UV(z=5)/ρ _UV(z=3)=0.8±0.4. We find clear clustering signals for both LBGs and LAEs, and estimate the correlation length (and the galaxy-dark matter bias) to be r ₀=5.1 ^+1.0_−1.1 and 5.9 ^+1.3_−1.7 h ⁻¹ Mpc (b _g=3.5 ^+0.6_−0.7 and 4.6 ^+0.9_−1.2 for L>L ^* LBGs at z=4 and 5, respectively. We find that the correlation length of L>L ^* LBGs is almost constant, ∼ 5h ⁻¹ Mpc, at z>3, while the bias monotonically increases with redshift at z>3. These findings support the biased galaxy formation picture.