Evolution of the Stellar Mass Function and Infrared Luminosity Function of Galaxies since $z = 1.2$. (arXiv:1902.02779v1 [astro-ph.GA])
<a href="http://arxiv.org/find/astro-ph/1/au:+Beare_R/0/1/0/all/0/1">Richard Beare</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_M/0/1/0/all/0/1">Michael Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pimbblet_K/0/1/0/all/0/1">Kevin Pimbblet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Taylor_E/0/1/0/all/0/1">Edward Taylor</a>
We measured evolution of the $K$-band luminosity function and stellar mass
function for red and blue galaxies at $z<1.2$ using a sample of 353 594 $I<24$
galaxies in 8.26 square degrees of Bo"otes. 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
$zsim1.1$ to $zsim0.3$, while the most luminous red (blue) galaxies decreased
in luminosity by 0.19 (0.33) mag or $times0.83 (0.74)$. 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 $times2.3$ from $zsim1.1$ to
$zsim0.3$, indicating a slowly decreasing rate of migration from the blue
cloud to the red sequence. Unlike some studies of the stellar mass function, we
find that massive red galaxies grow by a factor of $times1.7$ from $zsim1.1$
to $zsim0.3$, 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.
We measured evolution of the $K$-band luminosity function and stellar mass
function for red and blue galaxies at $z<1.2$ using a sample of 353 594 $I<24$
galaxies in 8.26 square degrees of Bo”otes. 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
$zsim1.1$ to $zsim0.3$, while the most luminous red (blue) galaxies decreased
in luminosity by 0.19 (0.33) mag or $times0.83 (0.74)$. 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 $times2.3$ from $zsim1.1$ to
$zsim0.3$, indicating a slowly decreasing rate of migration from the blue
cloud to the red sequence. Unlike some studies of the stellar mass function, we
find that massive red galaxies grow by a factor of $times1.7$ from $zsim1.1$
to $zsim0.3$, 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.
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