Abstract

Variability in AGN jet power is an expected consequence of fuelling mechanisms such as chaotic cold accretion. We simulate flickering jets to draw out potential observational probes of flickering behaviour. We use a Lagrangian particle approach coupled to high resolution relativistic hydrodynamic simulations, modelling the effects of shock acceleration together with radiative and adiabatic cooling. We introduce a new approach to modelling the effects of mixing with unshocked material – of crucial importance in an environment with a high density contrast. Our variable power simulations show bright hotspots lasting for small fractions of the jet’s lifetime, caused by the interaction between travelling shocks and the pre-existing shock structure at the jet head. We extend this work with an investigation of the effects of magnetic fields on jet dynamics and stability. I will discuss the potential role of the kink instability in these systems and present preliminary results from a constant and flickering jet simulation.