Dynamics and stability of magnetized AGN-blown bubbles in clusters of galaxies

Fuente: arXiv
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Autori principali: Mohov, Aleksey, Lyutikov, Maxim
Natura: Preprint
Pubblicazione: 2026
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author Mohov, Aleksey
Lyutikov, Maxim
author_facet Mohov, Aleksey
Lyutikov, Maxim
contents We perform MHD simulations of AGN-blown bubbles in the Intercluster Medium (ICM) containing large-scale coherent magnetic fields. We assume that bubbles, created by the intermittent jets from Active Galactic Nuclei, quickly relax to the Woltjer-Taylor spheromak-like state, with internal plasma beta-parameter $\sim 1$. We demonstrate that such bubbles rising through hydrostatically-stratified atmosphere are magnetically stabilized against fluid interface instabilities, remaining coherent for a long time. Typical velocity is $ v /c_s \sim \sqrt{R/H} \leq 1 $ ($c_s$ is sound speed, $R$ is the bubble size, $H$ is the scale height). Current-driven instabilities (internal kinks) lead to bubble's tilting, but develop on long time scales, and remain unimportant, leading to minor modifications of the internal structure. Our results explain apparent long-term stability of ICM cavities. Subsonically rising stable bubbles dissipate in their wake approximately the energy initially injected by the jet, and may efficiently reheat the clusters cores in a ``gentle'' way.
format Preprint
id arxiv_https___arxiv_org_abs_2603_24937
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Dynamics and stability of magnetized AGN-blown bubbles in clusters of galaxies
Mohov, Aleksey
Lyutikov, Maxim
Astrophysics of Galaxies
We perform MHD simulations of AGN-blown bubbles in the Intercluster Medium (ICM) containing large-scale coherent magnetic fields. We assume that bubbles, created by the intermittent jets from Active Galactic Nuclei, quickly relax to the Woltjer-Taylor spheromak-like state, with internal plasma beta-parameter $\sim 1$. We demonstrate that such bubbles rising through hydrostatically-stratified atmosphere are magnetically stabilized against fluid interface instabilities, remaining coherent for a long time. Typical velocity is $ v /c_s \sim \sqrt{R/H} \leq 1 $ ($c_s$ is sound speed, $R$ is the bubble size, $H$ is the scale height). Current-driven instabilities (internal kinks) lead to bubble's tilting, but develop on long time scales, and remain unimportant, leading to minor modifications of the internal structure. Our results explain apparent long-term stability of ICM cavities. Subsonically rising stable bubbles dissipate in their wake approximately the energy initially injected by the jet, and may efficiently reheat the clusters cores in a ``gentle'' way.
title Dynamics and stability of magnetized AGN-blown bubbles in clusters of galaxies
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2603.24937