Near-Infrared Spectroscopic Imaging Of The Circumnuclear Environment Of Ngc-1068

We report less than or equal to 1'' resolution imaging of the 1.6435 mu m [Fe II] and 2.1212 mu m = H-2 nu = 1-0 S(1) lines toward the nucleus of the Seyfert 2 galaxy NGC 1068. Our observations suggest that the near-infrared [Fe II] and H-2 emission, as well as the radio continuum and optical line emission observed toward the narrow-line region (NLR), arises at the interface between the nuclear outflow/radiation and dense (n(H-2)> 10(4) cm(-3)) circumnuclear molecular clouds. The [Fe II] emission extends over greater than or equal to 8'', is elongated along P.A. similar to 35 degrees and tracks the NLR and the central collimated part of the twin radio jet. The [Fe II] emission may be produced in gas exposed to nuclear X-ray radiation or in gas which is interacting with the outflow/jet from the active nucleus. We also find that the abundance of iron appears to be enhanced along the jet axis. We propose that this enhancement may be due to efficient grain destruction by the hard nuclear radiation or fast J-shocks produced in the outflow and/or due to an unusually high value of the total fractional abundance of iron compared to solar. When leaving the molecular disk, the outflow/jet enters less dense atomic gas at a much lower pressure which causes the jet to widen, seen both in the [Fe II] and radio emission. Alternatively, and less likely, the [Fe II] emission may be emitted in gas shocked by supernova remnants. In contrast, the H-2 emission is concentrated at the nucleus and extends similar to 5'' (340 pc) east-west, with several embedded knots which probably represent concentrations of dense, massive molecular clouds. The high signal-to-noise quality of these new data have enabled us to ascertain that the warm molecular gas is not symmetrically distributed about the near-infrared continuum peak as was previously suspected. Rather, the brightest H, knot is centered 0''.2+/-0.''3 southwest of the near-infrared continuum peak and, due to a total molecular hydrogen column density likely exceeding 10(23) cm(-2), may contribute significantly to the obscuration of the broad-line region in the nucleus of NGC 1068.