Speaker
Description
Active galactic nuclei (AGNs), powered by supermassive black holes, can launch relativistic jets that propagate over hundreds of kiloparsecs and interact with the extragalactic medium, producing terminal shocks and hotspots, which are hallmark features of Fanaroff–Riley II (FR II) sources. The radio galaxy Pictor A is a notable example of this class, exhibiting jets extending up to about 175 kpc and detected in X-rays, whose synchrotron emission indicates efficient particle acceleration. In addition, this source is considered a promising candidate for the acceleration of ultra-high-energy cosmic rays in the multimessenger context. In this work, we investigate the morphology and dynamics of the jet in Pictor A through 3D relativistic hydrodynamic simulations performed with the PLUTO code. We model the injection of an ultra-relativistic flow into a stratified medium in order to reproduce the formation of the western hotspot and the main observed structures. The results show the formation of hotspots and a morphology consistent with that of the source, consisting of a relativistic spine surrounded by a shear layer and a sub-relativistic cocoon. The shock analysis makes it possible to characterize the regions of strongest emission and to correlate the simulated structures with the observed profiles, contributing to the understanding of particle acceleration mechanisms in large-scale extragalactic jets.
| CPF | 07686233910 |
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