We report the detection of a diffuse radio halo source in the hottest known
cluster of galaxies 1E0658-56 (RXJ0658-5557). The radio halo has a morphology
similar to the X-ray emission from the hot intracluster medium. The detection
of such a strong radio halo in such a hot cluster is further evidence to the
link between X-ray temperature and cluster-wide radio halos. We describe a new
model for the origin of cluster-wide radio halo sources involving a direct
connection between the X-ray emitting thermal particles and the radio emitting
relativistic particles.Comment: 6 pages, 5 postscript figues, Latex, to appear in proceedings of the
Ringberg workshop on "Diffuse Thermal and Relativistic Plasma in Galaxy
Clusters", April 1999, H. Boehringer, L. Feretti, P. Schuecker (eds.
