2019ApJ...873...78B

We measured evolution of the K-band luminosity function and stellar mass function (SMF) for red and blue galaxies at z < 1.2 using a sample of 353 594 I < 24 galaxies in 8.26 square degrees of Bootes. We addressed several sources of systematic and random error in measurements of total galaxy light, photometric redshift, and absolute magnitude. We have found that the K-band luminosity density for both red and blue galaxies increased by a factor of 1.2 from z ∼ 1.1 to z ∼ 0.3, while the most luminous red (blue) galaxies decreased in luminosity by 0.19(0.33) mag or x0.83(0.74). These results are consistent with z < 0.2 studies, while our large sample size and area result in smaller Poisson and cosmic variance uncertainties than most z > 0.4 luminosity and mass function measurements. Using an evolving relation for K-band mass-to-light ratios as a function of (B-V) color, we found a slowly decreasing rate of growth in red galaxy stellar mass density of x2.3 from z ∼ 1.1 to z ∼ 0.3, indicating a slowly decreasing rate of migration from the blue cloud to the red sequence. Unlike some studies of the SMF, we find that massive red galaxies grow by a factor of x1.7 from z ∼ 1.1 to z ∼ 0.3, with the rate of growth due to mergers decreasing with time. These results are comparable with measurements of merger rates and clustering, and they are also consistent with the red galaxy stellar mass growth implied by comparing K-band luminosity evolution with the fading of passive stellar population models.