Uplifted cool gas and heating by mixing in cooling flows

TL;DR

This paper investigates how mixing of hot bubble gas with the intracluster medium in cooling flow clusters leads to heating and uplifted dense gas, emphasizing the significance of mixing over other processes like shocks and turbulence.

Contribution

It demonstrates through simulations that mixing-induced heating and uplifted gas are key processes in cooling flow clusters, highlighting their observational importance.

Findings

Uplifted dense gas is associated with hot bubble activity.

Mixing of hot bubble gas heats the intracluster medium.

Mixing contributes more to heating than shocks or turbulence.

Abstract

We analyze our earlier three-dimensional hydrodynamical numerical simulation of jet-inflated bubbles in cooling flow clusters, and find that dense gas that was not heated by the jets' activity and that resides around the hot jet-inflated bubbles can be identified as uplifted gas as observed in some clusters. During the build up of the dense gas around the hot bubble, mixing of hot bubble gas with other regions of the intracluster medium (ICM) heats the ICM. The vortices that mix the ICM with the hot bubble gas also excite shock waves, sound waves, and turbulence. Sound waves, shocks, turbulence, and uplifted gas, might be easier to detect than the mixing process and hence attract more attention, but we argue that the contributions of these processes to the heating of the ICM do not add up to the level of contribution of the mixing-heating process.