No CrossRef data available.
Published online by Cambridge University Press: 14 August 2015
The density of intergalactic gas may be an important parameter in the formation of extended radio sources. It may range from ∼ 0.1 particle cm−3 in the centres of some rich clusters of galaxies down to 10−8cm−3 or less in intercluster space. The possible influence of the intracluster gas surrounding NGC 1275 on its radio emission is discussed, and the possibility that a significant fraction of the X-ray background is due to a hot intergalactic medium is explored in some detail.