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

초록

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 deg(2) in the AKARI North Ecliptic Pole-Deep Field. Two-point correlation functions for two magnitude-limited cases, K-s < 21.1 (N = 234) and K-s < 21.5 (N = 428), are estimated using a single powerlaw function with the fixed slope of 0.8. The bias factors of sgzKs with K-s < 21.1 and 21.5 are 5.79 +/- 1.07 and 4.00 +/- 0.67, respectively, representing that sgzKs with z similar to 1.7 reside in dark matter haloes more massive than 10(13) M-circle dot. We find that haloes hosting sgzKs with K-s < 21.5 evolve into haloes that host local massive galaxies with similar to 6 L*. This suggests that sgzKs with K-s < 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 K-s < 21.5. The median values of stellar mass and star formation rate are 9.5 x 10(10) M-circle dot and 162 M-circle dot 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.

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