Ionized gas velocity dispersion in nearby dwarf galaxies: looking at
  supersonic turbulent motions
  We present the results of ionized gas turbulent motions study in several
nearby dwarf galaxies using a scanning Fabry-Perot interferometer with the 6-m
telescope of the SAO RAS. Combining the `intensity-velocity dispersion'
diagrams (I-sigma) with two-dimensional maps of radial velocity dispersion we
found a number of common patterns pointing to the relation between the value of
chaotic ionized gas motions and processes of current star formation. In five
out of the seven analysed galaxies we identified expanding shells of ionized
gas with diameters of 80-350 pc and kinematic ages of 1-4 Myr. We also
demonstrate that the I-sigma diagrams may be useful for the search of supernova
remnants, other small expanding shells or unique stars in nearby galaxies. As
an example, a candidate luminous blue variable (LBV) was found in UGC 8508. We
propose some additions to the interpretation, previously used by Munoz-Tunon et
al. to explain the I-sigma diagrams for giant star formation regions. In the
case of dwarf galaxies, a major part of the regions with high velocity
dispersion belongs to the diffuse low surface brightness emission, surrounding
the star forming regions. We attribute this to the presence of perturbed low
density gas with high values of turbulent velocities around the giant HII
regions.
