How relativistic jets from AGNs affect the host galaxy's ISM

     
Relativistic jets from AGNs are an important driver of feedback in galaxies with an active black hole. They first interact with the host galaxy's ISM before breaking out to larger scales, significantly affecting the galaxy's morphology and evolution. Cosmological simulations predict that massive galaxies undergo several such episodes in the course of their evolution. However, large scale simulations are unable to probe the impact of such AGN activity on the ISM of the host galaxy due to limited resolution. I shall present the results of our recent 3D relativistic hydrodynamic simulations, performed on scales of several kpc, of AGN jets interacting with an inhomogeneous turbulent ISM of a gas-rich galaxy. Our simulations, with a resolution of 6 pc, capture the interaction of the jet driven shocks and turbulence in the gas, often missed in large scale simulations. The relativistic jet initially couples strongly with the turbulent ISM, driving fast moving lateral outflows of dense gas. The resultant outflows though strong, do not escape the galaxy, supporting a galactic fountain scenario of feedback, rather than a blow out phase as envisaged in earlier models. In gas disks, inclined jets are found to have very different morphology of the resultant outflow, and larger coupling with the ISM. While AGN activity can potentially quench star formation by driving outflows or inducing turbulence, we find that they can also potentially enhance star formation (positive feedback) in localised patches. We explore the efficiency of such feedback processes in a suite of simulations with different jet power, ISM density, gas morphology (disk+spherical) and jet orientation. The results of our simulations show qualitative and quantitative similarities with observed results of jet-ISM interaction in several galaxies. I will discuss the observational signatures of such jet-ISM interactions predicted by our simulations (optical+radio) which will help constrain the models from observed results.