Kinematics of galaxies in Compact Groups. Studying the B-band
  Tully-Fisher relation
  We obtained new Fabry-Perot data cubes and derived velocity fields,
monochromatic and velocity dispersion maps for 28 galaxies in the Hickson
compact groups 37, 40, 47, 49, 54, 56, 68, 79 and 93. We find that one third of
the non-barred compact group galaxies have position angle misalignments between
the stellar and gaseous components. This and the asymmetric rotation curves are
clear signatures of kinematic perturbations, probably due to interactions among
compact group galaxies. A comparison between the B-band Tully-Fisher relation
for compact group galaxies and that for the GHASP field-galaxy sample shows
that, despite the high fraction of compact group galaxies with asymmetric
rotation curves, these lie on the Tully-Fisher relation defined by galaxies in
less dense environments, although with more scatter. This is in agreement with
previous results, but now confirmed for a larger sample of 41 galaxies. We
confirm the tendency for compact group galaxies at the low-mass end of the
Tully-Fisher relation (HCG 49b, 89d, 96c, 96d and 100c) to have either a
magnitude that is too bright for its mass (suggesting brightening by star
formation) and/or a low maximum rotational velocity for its luminosity
(suggesting tidal stripping). These galaxies are outside the Tully Fisher
relation, at the 1 sigma level, even when the minimum acceptable values of
inclinations are used to compute their maximum velocities. The inclusion of
such galaxies with v<100 km/s in the determination of the zero point and slope
of the compact group B-band Tully-Fisher relation would strongly change the
fit, making it different from the relation for field galaxies, a fact that has
to be kept in mind when studying scaling relations of interacting galaxies,
specially at high redshifts.
