Galaxy kinematics in the XMMU J2235-2557 cluster field at z~1.4
  We took spatially resolved slit FORS2 spectra of 19 cluster galaxies at
z=1.4, and 8 additional field galaxies at 1<z<1.2 using the ESO Very Large
Telescope. The targets were selected from previous spectroscopic and
photometric campaigns. Our spectroscopy was complemented with HST-ACS imaging
in the F775W and F850LP filters, which is mandatory to derive the galaxy
structural parameters accurately. We analyzed the ionized gas kinematics by
extracting rotation curves from the two-dimensional spectra. Taking into
account all geometrical, observational, and instrumental effects, we used these
rotation curves to derive the intrinsic maximum rotation velocity (Vmax). Vmax
was robustly determined for 6 cluster galaxies and 3 field galaxies. Galaxies
with sky contamination or insufficient spatial rotation curve extent were not
included in our analysis. We compared our sample to the local B-band
Tully-Fisher relation (TFR) and the local Velocity-Size relation (VSR), finding
that cluster galaxies are on average 1.6 mags brighter and a factor 2-3
smaller. We tentatively divided our cluster galaxies by total mass (i.e., Vmax)
to investigate a possible mass dependency in the environmental evolution of
galaxies. The average deviation from the local B-band TFR is -0.7 mags for the
high-mass subsample. This mild evolution may be driven by younger stellar
populations of distant galaxies with respect to their local counterparts, and
thus, an increasing luminosity is expected towards higher redshifts. However,
the low-mass group is made of 3 highly overluminous galaxies with average TFR
offsets of -2.4 mags. This deviation can no longer be explained by the gradual
evolution of SP with lookback time and thus, we suspect that we see rather
compact galaxies that got an enhancement of star formation during their infall
towards the dense regions of the cluster due to interactions with the
intracluster medium.
