Issue |
EAS Publications Series
Volume 44, 2010
JENAM 2008: Grand Challenges in Computational Astrophysics
|
|
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Page(s) | 63 - 68 | |
DOI | https://doi.org/10.1051/eas/1044011 | |
Published online | 20 January 2011 |
H. Wozniak and G. Hensler (eds)
EAS Publications Series, 44 (2010) 63-68
AGN-driven Turbulence in Galaxy Clusters
1
Jacobs University Bremen, PO Box 750561, 28725
Bremen,
Germany
2
School of Earth and Space Exploration, Arizona State University,
PO Box 871404,
Tempe, AZ
85287-1404,
USA
Hot, underdense bubbles powered by active galactic nuclei (AGN) are likely to play a key role in halting catastrophic cooling in the centers of cool-core galaxy clusters. We present three-dimensional simulations that capture the evolution of such bubbles, using an adaptive-mesh hydrodynamic code, FLASH3, to which we have added a subgrid model of turbulence and mixing. Pure-hydro simulations indicate that AGN bubbles are disrupted into resolution-dependent pockets of underdense gas. However, proper modeling of subgrid turbulence shows that Rayleigh-Taylor instabilities act to mix the heated regions with their surroundings, while at the same time preserving them as coherent structures, consistent with observations. Thus bubbles are transformed into hot clouds of mixed material as they move outwards in the hydrostatic intracluster medium. Properly capturing the evolution of such clouds has important implications for many ICM properties.
© EAS, EDP Sciences 2011