A jet-driven dynamo (JEDD) from jets-inflated bubbles in cooling flows

TL;DR

This paper proposes a jet-driven dynamo mechanism (JEDD) that amplifies magnetic fields in galaxy cluster cooling flows through turbulence and shear caused by jets and bubbles, with amplification timescales of about a hundred million years.

Contribution

It introduces the JEDD model as a new process for magnetic field amplification in cooling flows, linking turbulence and shear from jets and bubbles to magnetic field growth.

Findings

Magnetic field amplification occurs near jets and bubbles within ~100 million years.

Turbulence from vortices transfers energy from jets to the intra-cluster medium.

JEDD integrates magnetic fields into the jet-feedback cycle in cooling flows.

Abstract

I suggest that the main process that amplifies magnetic fields in cooling flows in clusters and group of galaxies is a jet-driven dynamo (JEDD). The main processes that are behind the JEDD is the turbulence that is formed by the many vortices formed in the inflation processes of bubbles, and the large scale shear formed by the propagating jet. It is sufficient that a strong turbulence exits in the vicinity of the jets and bubbles, just where the shear is large. The typical amplification time of magnetic fields by the JEDD near the jets and bubbles is approximately hundred million years. The amplification time in the entire cooling flow region is somewhat longer. The vortices that create the turbulence are those that also transfer energy from the jets to the intra-cluster medium, by mixing shocked jet gas with the intra-cluster medium gas, and by exciting sound waves. The JEDD model adds magnetic fields to the cyclical behavior of energy and mass in the jet-feedback mechanism (JFM) in cooling flows.