The complex, dusty narrow-line region of NGC 4388: Gas-jet interactions,
  outflows, and extinction revealed by near-IR spectroscopy
  We present Gemini/GNIRS spectroscopy of the Seyfert 2 galaxy NGC 4388, with
simultaneous coverage from 0.85 - 2.5 $\mu$m. Several spatially-extended
emission lines are detected for the first time, both in the obscured and
unobscured portion of the optical narrow line region (NLR), allowing us to
assess the combined effects of the central continuum source, outflowing gas and
shocks generated by the radio jet on the central 280 pc gas. The HI and [FeII]
lines allow us to map the extinction affecting the NLR. We found that the
nuclear region is heavily obscured, with E(B-V) ~1.9 mag. To the NE of the
nucleus and up to ~150 pc, the extinction remains large, ~1 mag or larger,
consistent with the system of dust lanes seen in optical imaging. We derived
position-velocity diagrams for the most prominent lines as well as for the
stellar component. Only the molecular gas and the stellar component display a
well-organized pattern consistent with disk rotation. Other emission lines are
kinematically perturbed or show little evidence of rotation. Extended
high-ionization emission of sulfur, silicon and calcium is observed to
distances of at least 200 pc both NE and SW of the nucleus. We compared flux
ratios between these lines with photoionization models and conclude that
radiation from the central source alone cannot explain the observed
high-ionization spectrum. Shocks between the radio-jet and the ambient gas are
very likely an additional source of excitation. We conclude that NGC 4388 is a
prime laboratory to study the interplay between all these mechanisms.
