gzK-colour-selected star-forming galaxies in the AKARI NEP-Deep Field

Abstract

ABSTRACT We study the clustering property and physical parameters of gzK-colour-selected star-forming galaxies (sgzKs) based on the Canada–France–Hawaii Telescope surveys over 0.55 deg2 in the AKARI North Ecliptic Pole-Deep Field. Two-point correlation functions for two magnitude-limited cases, Ks < 21.1 (N = 234) and Ks < 21.5 (N = 428), are estimated using a single power-law function with the fixed slope of 0.8. The bias factors of sgzKs with Ks < 21.1 and 21.5 are 5.79 ± 1.07 and 4.00 ± 0.67, respectively, representing that sgzKs with z ∼ 1.7 reside in dark matter haloes more massive than $10^{13} ~\rm M_{\odot }$. We find that haloes hosting sgzKs with Ks < 21.5 evolve into haloes that host local massive galaxies with ∼6 L*. This suggests that sgzKs with Ks < 21.5 are likely to be predecessors of local massive galaxies. The evolutionary track of bias factor for host haloes of the bright sgzKs is similar to that of the bright passive extremely red objects, implying a possible connection between the two populations of galaxies. From the spectral energy distribution fitting, we estimate physical parameters and active galactic nucleus (AGN) contribution for 75 mid-infrared (MIR)-detected sgzKs with Ks < 21.5. The median values of stellar mass and star formation rate are 9.5 × 1010$\rm M_{\odot }$ and 162 $\rm M_{\odot }$ yr−1, respectively. MIR-detected sgzKs have a variety of AGN contributions ranging from 0 to 80 per cent. The number ratio of sgzKs with larger AGN contribution than 10 per cent is 30 per cent.