A&A 464, 143-154 (2007)
DOI: 10.1051/0004-6361:20066427

Buoyant bubbles in a cooling intracluster medium

I. Hydrodynamic bubbles

A. Gardini<sup>1, 0, 2

1</sup>  Department of Astronomy, University of Illinois at Urbana-Champaign, Urbana, IL, 61801, USA
    e-mail: gardini@astro.uiuc.edu
²  National Center for Supercomputing Applications, Urbana, IL, 61801, USA

(Received 21 September 2006 / Accepted 9 November 2006)

Abstract
Aims.Over the past several years, numerous examples of X-ray cavities coincident with radio sources have been observed in so-called "cool core" clusters of galaxies. Motivated by these observations, we explore the evolution and the effect of cavities on a cooling intracluster medium (ICM) numerically, adding relevant physics step by step.
Methods.In this paper we present a first set of hydrodynamical, high resolution (1024³ effective grid elements), three-dimensional simulations, together with two-dimensional test cases. The simulations follow the evolution of radio cavities, modeled as bubbles filled by relativistic plasma, in the cluster atmosphere, while the ICM is subject to cooling.
Results.We find that the bubble rise retards the development of a cooling flow by inducing motions in the ICM, which repeatedly displace the material in the core. Even bubbles initially set significantly far from the cluster center affect the cooling flow, although much later than the beginning of the simulation. The effect is, however, modest: the cooling time is increased by at most only 25%. As expected, the overall evolution of pure hydrodynamic bubbles is at odds with observations, showing that some additional physics has to be considered to match the data.

Key words: galaxies: clusters: general -- cooling flows -- methods: numerical

© ESO 2007

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.

• If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
• You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
• You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.