STRICT LIMITS ON THE IONIZING LUMINOSITY IN NGC-1068 FROM JET-AXIS MOLECULAR CLOUDS

The radio jet axis of NGC 1068 is characterised by energetic activity from x-ray to radio wavelengths. Detailed kinematic and polarization s tudies have shown that this activity is confined to bipolar cones cent ered on the AGN which intersect the plane of the disk. Thus, molecular clouds at 1 kpc distance along this axis are an important probe of th e nuclear ionizing luminosity and spectrum. Extended 10.8 mu m emissio n coincident with the clouds is reasonably understood by dust heated t o high temperatures by the nuclear radiation field. This model predict s that the nuclear spectrum is quasar-like (power law + blue excess) w ith a luminosity 2-5 times higher than inferred by Pier et al. (1994). Consequently, there is little or no polyaromatic hydrocarbon (PAH) em ission associated with the radio-axis molecular clouds. We review this model in the light of new observations. A multi-waveband collage is i ncluded to illustrate the possible orientations of the double cones to our line of sight and the galaxian plane.