GOLDRUSH. IV. Luminosity Functions and Clustering Revealed with ∼4,000,000 Galaxies at z ∼ 2-7: Galaxy-AGN Transition, Star Formation Efficiency, and Implication for Evolution at z > 10

We present new measurements of rest-UV luminosity functions and angular correlation functions from 4,100,221 galaxies at z similar to 2-7 identified in the Subaru/Hyper Suprime-Cam survey and CFHT Large Area U-band Survey. The obtained luminosity functions at z similar to 4-7 cover a very wide UV luminosity range of similar to 0.002-2000L(UV)(*) combined with previous studies, confirming that the dropout luminosity function is a superposition of the active galactic nucleus (AGN) luminosity function dominant at M-UV less than or similar to -24 mag and the galaxy luminosity function dominant at M-UV greater than or similar to -22 mag, consistent with galaxy fractions based on 1037 spectroscopically identified sources. Galaxy luminosity functions estimated from the spectroscopic galaxy fractions show the bright-end excess beyond the Schechter function at greater than or similar to 2 sigma levels, possibly made by inefficient mass quenching, low dust obscuration, and/or hidden AGN activity. By analyzing the correlation functions at z similar to 2-6 with HOD models, we find a weak redshift evolution (within 0.3 dex) of the ratio of the star formation rate (SFR) to the dark matter accretion rate, SFR/<(M)over dot>(h) 10 with proportional to 10(-0.5(1+z)), which will be directly tested with the James Webb Space Telescope.

Automated summary

This study presents new measurements of rest-UV luminosity functions and angular correlation functions of galaxies at redshifts around 2-7. The findings confirm previous studies and reveal the existence of a bright-end excess in the galaxy luminosity function, possibly attributed to inefficient mass quenching, low dust obscuration, and/or hidden AGN activity. Additionally, the study shows a weak redshift evolution in the ratio of star formation rate to dark matter accretion rate, which will be further tested by the James Webb Space Telescope.