Near-IR Galaxy Counts and Evolution from the Wide-Field ALHAMBRA survey
  The ALHAMBRA survey aims to cover 4 square degrees using a system of 20
contiguous, equal width, medium-band filters spanning the range 3500 A to 9700
A plus the standard JHKs filters. Here we analyze deep near-IR number counts of
one of our fields (ALH08) for which we have a relatively large area (0.5 square
degrees) and faint photometry (J=22.4, H=21.3 and K=20.0 at the 50% of recovery
efficiency for point-like sources). We find that the logarithmic gradient of
the galaxy counts undergoes a distinct change to a flatter slope in each band:
from 0.44 at [17.0, 18.5] to 0.34 at [19.5, 22.0] for the J band; for the H
band 0.46 at [15.5, 18.0] to 0.36 at [19.0, 21.0], and in Ks the change is from
0.53 in the range [15.0, 17.0] to 0.33 in the interval [18.0, 20.0]. These
observations together with faint optical counts are used to constrain models
that include density and luminosity evolution of the local type-dependent
luminosity functions. Our models imply a decline in the space density of
evolved early-type galaxies with increasing redshift, such that only 30% - 50%
of the bulk of the present day red-ellipticals was already in place at z~1.
