Jets: an environmental impact statement

Abstract

We review our recent work on the interaction of jets with the interstellar medium of both classical double and young radio galaxies. We propose explanations for the intriguing radio morphology of Hercules A and Pictor A in terms of the complex structure produced near the terminal shock in the jet. This also has ramifications for the interpretation of the high energy emission from Pictor A. Gigahertz Peak Spectrum (GPS) and Compact Steep Spectrum (CSS) sources are now believed to be young radio galaxies in which the jets are interacting with an inhomogeneous interstellar medium. Two dimensional slab-jet simulations of jets interacting with a clumpy interstellar medium show the way in which radiative shocks are driven into the clouds and how the jet is disrupted. There are interesting morphological comparisons between one of our simulations and the GPS source 4C31.05 and the large scale structure of M87. Another simulation with a lower filling factor, resembles the CSS quasar 3C48.