# Jet-torus connection in radio galaxies: Relativistic hydrodynamics and synthetic emission

## TL;DR

This study uses relativistic hydrodynamic simulations and synthetic emission modeling to explore how the ambient medium and obscuring torus influence jet asymmetries in radio galaxies, aligning simulation results with VLBI observations.

## Contribution

It introduces a comprehensive simulation framework combining hydrodynamics and emission modeling to analyze jet-ambient medium interactions and their observational signatures.

## Key findings

- Jet asymmetries can result from ambient medium interactions.
- Obscuring torus absorption affects jet emission appearance.
- Simulated radio maps match observed asymmetries.

## Abstract

High-resolution Very-Long-Baseline Interferometry observations of active galactic nuclei have revealed asymmetric structures in the jets of radio galaxies. These asymmetric structures may be due to internal asymmetries in the jet, could be induced by the different conditions in the surrounding ambient medium including the obscuring torus, or a combination of the two. In this paper we investigate the influence of the ambient medium (including the obscuring torus) on the observed properties of jets from radio galaxies. We performed special-relativistic hydrodynamic (RHD) simulations of over-pressured and pressure-matched jets using the special-relativistic hydrodynamics code \texttt{Ratpenat}, which is based on a second-order accurate finite-volume method and an approximate Riemann solver. Using a newly developed emission code to compute the electromagnetic emission, we have investigated the influence of different ambient medium and torus configurations on the jet structure and subsequently computed the non-thermal emission produced by the jet and the thermal absorption due to the torus. To better compare the emission simulations with observations we produced synthetic radio maps, taking into account the properties of the observatory. The detailed analysis of our simulations shows that the observed asymmetries can be produced by the interaction of the jet with the ambient medium and by the absorption properties of the obscuring torus.