Jet cocoons and the formation of narrow-line clouds in Seyfert galaxies
Por:
Steffen W., Gómez J.L., Williams R.J.R., Raga A.C., Pedlar A.
Publicada:
1 ene 1997
Resumen:
We present non-adiabatic hydrodynamic simulations of a supersonic light jet propagating into a fully ionized medium of uniform density on a scale representative of the narrow-line region (NLR) in Seyfert galaxies with associated radio jets. In this regime the cooling distance of the swept-up gas in the bowshock of the jet is of the same order as the transverse extent of the jet bowshock, as opposed to the more extreme regimes found for more powerful adiabatic large-scale jets or the slow galactic jets which have previously been simulated. We calculate the emissivity for the H? line and for radio synchrotron emission. We find that the structure of the line-emitting cold envelope of the jet cocoon is strongly dependent on the nonstationary dynamics of the jet head as it propagates through the ambient medium. We observe the formation of cloud-like high density regions which we associate with NLR clouds and filaments. We find that some of these clouds might be partially neutral and represent sites of jet-induced star formation. The calculated H? flux and the spectral line width are consistent with NLR observations. The simulation of the radio-optical emission with radiative cooling confirms the basic result of the geometric bowshock model developed by Taylor et al., i.e. that the start of noticeable optical line emission can be significantly offset from the hotspot of the radio emission. However, the time-dependent nature of the jet dynamics implies significant differences from Taylor et al.'s geometric bowshock model. © 1997 RAS.
Filiaciones:
Steffen W.:
Department of Physics and Astronomy, University of Manchester, Schuster Laboratory, Oxford Road, Manchester M13 9PL, United Kingdom
Gómez J.L.:
Department of Physics and Astronomy, University of Manchester, Schuster Laboratory, Oxford Road, Manchester M13 9PL, United Kingdom
Inst. de Astrofis. de Andalucia, CSIC, Apdo. 3004, Granada 18080, Spain
Williams R.J.R.:
Department of Physics and Astronomy, University of Manchester, Schuster Laboratory, Oxford Road, Manchester M13 9PL, United Kingdom
Department of Physics and Astronomy, The University, Leeds LS2 9JT, United Kingdom
Raga A.C.:
Instituto de Astronomía, UNAM, Apdo. Postal 70-264, 04510 México, D.F., Mexico
Pedlar A.:
Nuffield Radio Astron. Laboratories, University of Manchester, Jodrell Bank, Macclesfield, Cheshire SK11 9DL, United Kingdom
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