Kinematics of Arp 270: gas flows, nuclear activity and two regimes of
  star formation
  We have observed the Arp 270 system (NGC 3395 & NGC 3396) in H{\alpha}
emission using the GH{\alpha}FaS Fabry-Perot spectrometer on the 4.2m William
Herschel Telescope (La Palma). In NGC 3396, which is edge-on to us, we detect
gas inflow towards the centre, and also axially confined opposed outflows,
characteristic of galactic superwinds, and we go on to examine the possibility
that there is a shrouded AGN in the nucleus. The combination of surface
brightness, velocity and velocity dispersion information enabled us to measure
the radii, FWHM, and the masses of 108 HII regions in both galaxies. We find
two distinct modes of physical behaviour, for high and lower luminosity
regions. We note that the most luminous regions show especially high values for
their velocity dispersions and hypothesize that these occur because the higher
luminosity regions form from higher mass, gravitationally bound clouds while
those at lower luminosity HII regions form within molecular clouds of lower
mass, which are pressure confined.
