Using a sample of \sim 410 000 galaxies to depth I _ { \textrm { AB } } = 24 over 8.26 deg ^ { 2 } in the Boötes field ( \sim 10 times larger than z \sim 1 luminosity function studies in the prior literature ) , we have accurately measured the evolving B -band luminosity function of red galaxies at z < 1.2 and blue galaxies at z < 1.0 .
In addition to the large sample size , we utilise photometry that accounts for the varying angular sizes of galaxies , photometric redshifts verified with spectroscopy , and absolute magnitudes that should have very small random and systematic errors .
Our results are consistent with the migration of galaxies from the blue cloud to the red sequence as they cease to form stars , and with downsizing in which more massive and luminous blue galaxies cease star formation earlier than fainter less massive ones .
Comparing the observed fading of red galaxies with that to be expected from passive evolution alone , we find that the stellar mass contained within the red galaxy population has increased by a factor of \sim 3.6 from z \sim 1.1 to z \sim 0.1 .
The bright end of the red galaxy luminosity function fades with decreasing redshift , the rate of fading increasing from \sim 0.2 mag per unit redshift at z = 1.0 to \sim 0.8 at z = 0.2 .
The overall decrease in luminosity implies that the stellar mass in individual highly luminous red galaxies increased by a factor of \sim 2.2 from z = 1.1 to z = 0.1 .