Large-scale Propagation of Very Light Jets in Galaxy Clusters

TL;DR

This paper uses MHD simulations to study very light jets in galaxy clusters, revealing their weak shocks, broad cocoons, and efficient energy thermalization, which align with radio and X-ray observations.

Contribution

It introduces detailed MHD simulations of extremely light jets in galaxy clusters, highlighting their dynamics and observational signatures.

Findings

Jets exhibit weak, roundish bow shocks.

Jets thermalize kinetic energy efficiently.

Backflows and turbulence influence jet appearance.

Abstract

We performed MHD simulations of very light bipolar jets with density contrasts down to 10^-4 in axisymmetry, which were injected into a medium of constant density and evolved up to 200 kpc (200 r_j) full length. These jets show weak and roundish bow shocks as well as broad cocoons and thermalize their kinetic energy very efficiently. We argue that very light jets are necessary to match low-frequency radio observations of radio lobes as well as the bow shocks seen in X-rays. Due to the slow propagation, the backflows and their turbulent interaction in the midplane are important for a realistic global appearance.