Molecular Hydrogen and [Fe II] in Active Galactic Nuclei III: LINERS and
  Star Forming Galaxies
  We study the kinematics and excitation mechanisms of H2 and [Fe II] lines in
a sample of 67 emission-line galaxies with Infrared Telescope Facility SpeX
near-infrared (NIR, 0.8-2.4 micrometers) spectroscopy together with new
photoionisation models. H2 emission lines are systematically narrower than
narrow-line region (NLR) lines, suggesting that the two are, very likely,
kinematically disconnected. The new models and emission-line ratios show that
the thermal excitation plays an important role not only in active galactic
nuclei but also in star forming galaxies. The importance of the thermal
excitation in star forming galaxies may be associated with the presence of
supernova remnants close to the region emitting H2 lines. This hypothesis is
further supported by the similarity between the vibrational and rotational
temperatures of H2. We confirm that the diagram involving the line ratios H2
2.121/Br_gamma and [Fe II] 1.257/Pa_beta is an efficient tool for separating
emission-line objects according to their dominant type of activity. We suggest
new limits to the line ratios in order to discriminate between the different
types of nuclear activity.
