Formation of ionization-cone structures in active galactic nuclei: II. Nonlinear hydrodynamic modelling

In Part I of this paper (Paper I) we described an equilibrium model of a jet in the gravitational field corresponding to the rigid-rotation region of the galactic disk. We used linear stability analysis to find the waveguide-resonance instability of internal gravity waves due to the superreflection of these waves from the jet boundary. In this part of the paper, we perform nonlinear numerical 2D and 3D simulations of the development of this instability. We show that the shocks produced by this instability in the ambient medium of the jet are localized inside a cone with a large opening angle and are capable of producing features that are morphologically similar to those observed in galaxies with active nuclei (NGC 5252 for example).