THE JET DRIVEN MOTIONS IN THE NARROW-LINE REGION OF NGC-1068

Citation
Dj. Axon et al., THE JET DRIVEN MOTIONS IN THE NARROW-LINE REGION OF NGC-1068, Astrophysics and space science, 248(1-2), 1997, pp. 69-77
Citations number
27
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
0004640X
Volume
248
Issue
1-2
Year of publication
1997
Pages
69 - 77
Database
ISI
SICI code
0004-640X(1997)248:1-2<69:TJDMIT>2.0.ZU;2-4
Abstract
We have obtained RST FOC f/48 long-slit spectroscopy of the central 2 arcseconds of the Narrow Line Region of NGC 1068 between 3500-5400 Ang strom with a spectral resolution of 1.78 Angstrom/pixel. At a spatial scale of 0 ''.0287 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. Our results show that, within +/-0 ''.5 of the radio-jet tile emi ssion lines are split into two components whose velocity separation is 1500 km s(-1). The emission line structure is reminiscent of that see n previously around the jet of 3C120. Furthermore, this material envel oping the radio-jet is in a much higher ionization state than that of the surrounding NLR gas. The highest excitation is coincident with the jet axis where emission in the coronal line of [FeVII] lambda 3769 An gstrom is detected but where [OII] lambda 3727 Angstrom is depressed. These results imply that we are witnessing a cocoon of hot gas in expa nsion around the radio-jet created by its interaction with the gas, an d that these shocks are sufficiently fast, at least +/-700 km s(-1), t hat they are cresting localized ionization effects.