Evolution of the Fundamental Plane of 0.2<z<1.2 Early-type galaxies in
  the EGS
  The Fundamental Plane relates the structural properties of early-type
galaxies such as its surface brightness and effective radius with its dynamics.
The study of its evolution has therefore important implications for models of
galaxy formation and evolution. This work aims to identify signs of evolution
of early-type galaxies through the study of parameter correlations using a
sample of 135 field galaxies extracted from the Extended Groth Strip in the
redshift range 0.2<z<1.2. Using DEEP2 data, we calculate the internal velocity
dispersions by extracting the stellar kinematics from absorption line spectra,
using a maximum penalized likelihood approach. Morphology was determined
through visual classification using the V+I images of ACS. The structural
parameters of these galaxies were obtained by fitting de Vaucouleurs stellar
profiles to the ACS I-band images, using the GALFIT code. S\'ersic and
bulge-to-disc decomposition models were also fitted to our sample of galaxies,
and we found a good agreement in the Fundamental Plane derived from the three
models. Assuming that effective radii and velocity dispersions do not evolve
with redshift, we have found a brightening of 0.68 mag in the B-band and 0.52
mag in the g-band at <z>=0.7. However, the scatter in the FP is reduced by half
when we allow the FP slope to evolve, suggesting a different evolution of
early-type galaxies according to their intrinsic properties. The study of the
Kormendy relation shows the existence of a population of very compact (Re<2
Kpc) and bright galaxies (-21.5>Mg>-22.5), of which there are only a small
fraction (0.4%) at z=0. The evolution of these compact objects is mainly caused
by an increase in size that could be explained by the action of dry minor
mergers, and this population is responsible for the evolution detected in the
Fundamental Plane.
