Magnetic Fields and Radio Halos in Galaxy Clusters
By P. C. Tribble
ABSTRACT
Direct evidence for magnetic fields in galaxy clusters is given
by the existence of radio halos. Excess Faraday Rotation has also been
observed in a large sample of clusters. Combined with an estimate of
the tangling length of the field given by the smoothness of the radio
halo, this suggests that microGauss fields tangled on 10 kpc scales
are present in galaxy clusters. The origin of the field is most likely
the left-over remains of old radio sources in the cluster.
This paper appeared in the Contributed Papers of the NATO ASI on
Cosmical Magnetism, in honour of Professor L Mestel FRS, held in
Cambridge on the 5th-9th July 1993
Peter Tribble, peter.tribble@gmail.com