  Combining resolved optical spectroscopy with panoramic HST imaging, we study
the dynamical properties of spiral galaxies as a function of position across
two intermediate redshift clusters, and we compare the cluster population to
field galaxies in the same redshift range. By modelling the observed rotation
curves, we derive maximal rotation velocities for 40 cluster spirals and 37
field spirals, yielding one of the largest matched samples of cluster and field
spirals at intermediate redshift. We construct the Tully-Fisher relation in
both V and K_S bands, and find that the cluster Tully-Fisher relation exhibits
significantly higher scatter than the field relation, in both V and K_S bands.
Under the assumption that this increased scatter is due to an interaction with
the cluster environment, we examine several dynamical quantities (dynamical
mass, mass-to-light ratio, and central mass density) as a function of cluster
environment. We find that the central mass densities of star-forming spirals
exhibit a sharp break near the cluster Virial radius, with spirals in the
cluster outskirts exhibiting significantly lower densities. We argue that the
lower-density spirals in the cluster outskirts, combined with the high scatter
in both K_S- and V-band TF relations, demonstrate that cluster spirals are
kinematically disturbed by their environment, even as far as 2R_VIR from the
cluster center. We propose that such disturbances may be due to a combination
of galaxy merging and harassment.
