The origin of magnetic fields in galaxy clusters
By P. C. Tribble
Abstract
It is proposed that the magnetic fields in clusters of galaxies
originated in radio galaxies and have been dispersed throughout the
cluster and mixed in with the thermal plasma by cluster mergers.
Integrating over the radio luminosity function and the age of the
universe gives an accumulated energy density in radio source remnants
of 10^48 J Mpc^-3 at the present day. As the majority of powerful
radio sources were in clusters or in smaller structures that were
later incorporated into rich galaxy clusters, the majority of this
magnetic energy is now incorporated into the intracluster medium. The
energy available is 10^54 J per cluster, which is more than adequate
to give fields of microGauss strength. Most of the magnetic energy was
generated at high redshifts so that the magnetic fields in clusters at
redshifts of order unity should have built up to almost their present
strength.
Key words: magnetic fields -- galaxies: clustering -- radio continuum:
galaxies
Contents:
- Introduction
- The cluster radio source population
- The magnetic energy content of radio sources
- Integrating over the Radio Luminosity Function
- The energy per cluster
- Dispersing the field
- Conclusions
- Acknowledgments
- References
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Peter Tribble, peter.tribble@gmail.com