INFRARED AND VISIBLE CORONAL LINES IN NGC-1068

Infrared observations of [SiIX], [SM] [SiVII], [SiVI], and [CaVIII] co ronal line emission in NGC 1068 are presented and discussed together w ith visible spectra covering [FeVII], [FeX], [FeXI] and [SVIII]. These lines are found to peak similar or equal to 50 pc NE of the nucleus a nd appear to arise predominantly in outflowing gas within the prominen t ionization cone aligned with the radio jet. The line ratios argue ag ainst collisional ionization but could be explained with photoionizati on by radiation from the active nucleus. The observed [SiIX](3.935 mu m)/[SiVI](1.96 mu m) ratio is similar or equal to 10(3) larger than in NGC 6302, one of the highest excitation planetary nebulae known, demo nstrating both that photoionization by hot stars is excluded and the p otential value of the [SiIX](3.935 mu m) line as a tracer of AGN activ ity in visually obscured galactic nuclei.