Disk galaxy scaling relations at intermediate redshifts - I. The
  Tully-Fisher and velocity-size relations
  We took spatially resolved slit spectra of 261 field disk galaxies at
redshifts up to z~1 using the FORS instruments of the ESO Very Large Telescope.
Our spectroscopy was complemented with HST/ACS imaging in the F814W filter. We
analyzed the ionized gas kinematics by extracting rotation curves from the 2-D
spectra. Taking into account all geometrical, observational and instrumental
effects, these rotation curves were used to derive the intrinsic Vmax.
Neglecting galaxies with disturbed kinematics or insufficient spatial rotation
curve extent, Vmax could be robustly determined for 124 galaxies covering
redshifts 0.05<z<0.97. This is one of the largest kinematic samples of distant
disk galaxies to date. We compared this data set to the local B-band
Tully-Fisher relation and the local velocity-size relation. The scatter in both
scaling relations is a factor of ~2 larger at z~0.5 than at z~0. The deviations
of individual distant galaxies from the local Tully-Fisher relation are
systematic in the sense that the galaxies are increasingly overluminous towards
higher redshifts, corresponding to an over-luminosity of -(1.2+-0.5) mag at
z=1. This luminosity evolution at given Vmax is probably driven by younger
stellar populations of distant galaxies with respect to their local
counterparts, potentially combined with modest changes in dark matter mass
fractions. The analysis of the velocity-size relation reveals that disk
galaxies of a given Vmax have grown in size by a factor of ~1.5 over the past
~8 Gyr, likely via accretion of cold gas and/or small satellites. Scrutinizing
the combined evolution in luminosity and size, we find that the galaxies which
show the strongest evolution towards smaller sizes at z~1 are not those which
feature the strongest evolution in luminosity, and vice versa. [abstract
abbreviated]
