Previous abstract Next abstract
Session 39 - AGNs, QSOs, Active Galaxies.
Display session, Wednesday, June 11
South Main Hall,
We have obtained HST FOC f/48 long--slit spectroscopy of the Narrow Line Regions of NGC 1068,NGC 4151 amp; MKN 3 between 3500-5400Å\ with a spectral resolution of 1.78Åpixel. At a spatial scale of 0\farcs0287 per pixel these data provide an order of magnitude improvement in resolution over previous ground based spectra and allow us to trace the interaction between the radio jet and the gas in the NLR in each of these galaxies. Our results show that in each case, within \pm 0\farcs5 of the radio-jet the emission lines are split into two components whose velocity separation is typically 1000 km \mboxs^-1. The emission line structure is reminiscent of that seen previously around the jet of 3C120. Furthermore, this material enveloping the radio-jet is in a much higher ionization state than that of the surrounding NLR gas. In NGC 1068 the highest excitation is coincident with the jet axis where emission in the coronal line of [FeVII] \lambda 3769Å\ is detected but where [OII] \lambda3727 Å\ is depressed. These results imply that we are witnessing a cocoon of hot gas in expansion around the radio-jet created by its interaction with the gas, and that these shocks are sufficiently fast, at least \pm 700 km \mboxs^-1, that they are creating localized ionization effects.
Program listing for Wednesday