Rising Jet-Inflated Bubbles in Clusters of Galaxies

TL;DR

This study uses 2.5D hydrodynamical simulations to demonstrate that jet-inflated bubbles in galaxy clusters are stable and can travel large distances, primarily due to the dense shell formed during inflation, challenging the need for magnetic stabilization.

Contribution

It provides the first detailed hydrodynamical simulation showing the stability of jet-inflated bubbles in galaxy clusters and explains the physical reasons behind their stability.

Findings

Jet-inflated bubbles are stable and reach large distances in clusters.

Stability is mainly due to the dense shell formed during inflation.

Artificial bubbles without inflation are rapidly destroyed.

Abstract

We conduct two-dimensional axisymmetric (referred to as 2.5D) hydrodynamical numerical simulations of bubble evolution in clusters of galaxies. We inflate bubbles using slow, massive jets with a wide opening angle, and follow their evolution as they rise through the intra-cluster medium (ICM). We find that these jet-inflated bubbles are quite stable, and can reach large distances in the cluster while still maintaining their basic structure. The stability of the jet-inflated bubble comes mainly from the dense shell that forms around it during it's inflation stage, and from the outward momentum of the bubble and the shell. On the contrary, bubbles that are inserted by hand onto the grid and not inflated by a jet, i.e., an artificial bubble, lack these stabilizing factors, therefore, they are rapidly destroyed. The stability of the jet-inflated bubble removes the demand for stabilizing magnetic fields in the bubble.