A&A 384, L27-L30 (2002)
Radio and X-ray detectability of buoyant radio plasma bubbles in clusters of galaxiesT. A. Enßlin and S. Heinz
Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, Postfach 1317, 85741 Garching, Germany
(Received 18 January 2002 / Accepted 5 February 2002)
The Chandra X-ray Observatory is finding a surprisingly large number of cavities in the X-ray emitting intracluster medium (ICM), produced by the release of radio plasma from active galactic nuclei. In this letter, we present simple analytic formulae for the evolution of the X-ray deficit and for the radio spectrum of a buoyantly rising bubble. The aim of this work is to provide a theoretical framework for the planning and the analysis of X-ray and radio observations of galaxy clusters. We show that the cluster volume tested for the presence of cavities by X-ray observations is a strongly rising function of the sensitivity.
Key words: radiation mechanisms: thermal -- radiation mechanism: non-thermal -- galaxies: active -- intergalactic medium -- galaxies: cluster: general -- radio continuum: general
Offprint request: T. A. Enßlin, firstname.lastname@example.org
© ESO 2002