Intracluster Medium reheating by relativistic jets

TL;DR

This paper presents the first relativistic simulations of galactic jets, revealing their role in efficiently reheating the intra-cluster medium through long-lived shock waves, which produce observable X-ray cavities.

Contribution

It introduces the first relativistic, long-term simulations of galactic jets, showing their impact on intra-cluster medium reheating and cavity formation, differing from previous non-relativistic models.

Findings

No buoyant bubbles observed, instead large cocoon regions form.

Reheating is more efficient and faster due to shock waves.

X-ray cavities remain confined by weak shocks for hundreds of millions of years.

Abstract

Galactic jets are powerful energy sources reheating the intra-cluster medium in galaxy clusters. Their crucial role in the cosmic puzzle, motivated by observations, has been established by a great number of numerical simulations missing the relativistic nature of these jets. We present the first relativistic simulations of the very long term evolution of realistic galactic jets. Unexpectedly, our results show no buoyant bubbles, but large cocoon regions compatible with the observed X-ray cavities. The reheating is more efficient and faster than in previous scenarios, and it is produced by the shock wave driven by the jet, that survives for several hundreds of Myrs. Therefore, the X-ray cavities in clusters produced by powerful relativistic jets would remain confined by weak shocks for extremely long periods, whose detection could be an observational challenge.