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T.E. Clarke (National Radio Astronomy Observatory)
Clusters of galaxies form by gravitational merger of smaller clusters and subclusters. In a major cluster merger event, shocks and turbulence can dissipate more than 1063 ergs of energy into the intracluster medium. This energy can go into shock heating of the thermal gas, particle acceleration, and amplification of intracluster magnetic fields. Radio observations toward clusters with signatures of current or recent merger activity sometimes reveal the presence of large regions of diffuse, steep-spectrum synchrotron emission. This radio emission has no optical counterpart and appears to be tied directly to the intracluster medium rather than any individual cluster member. More relaxed cluster systems often have very dense (cooling-flow) cores which show complex X-ray morphologies. Powerful central radio sources in these relaxed clusters appear to be strongly interacting with the thermal cluster gas. In a number of relaxed cluster systems the central radio source appear to be displacing the dense thermal gas, resulting in X-ray depressions. I will review the recent results from new high-sensitivity, high-resolution radio and X-ray observations of the interactions of the thermal and non-thermal components of the intracluster medium. The combination of the new capabilities in both of these wavelength regimes is providing unique details on the physics of the intracluster medium.
The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
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Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.