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Constraints Imposed by a High Magnetic Field on Models for the EUV Emission in the Coma Cluster

Ming Yann Tsay·Chorng-Yuan Hwang·Stuart Bowyer
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Abstract

A variety of models have been explored in regard to the origin of the excess extreme ultraviolet (~ 0.1 keV) emission in the Coma cluster. It is now established that the flux is non-thermal and the only non-thermal source mechanism that appears viable is inverse Compton emission produced by ~ 100 MeV electrons interacting with the cosmic microwave background photons. All but one of the models that have been proposed require a cluster magnetic field < 1 micro G. However, recent observations strongly suggest the magnetic field in the Coma cluster is ~ 5 micro G. We investigate the constraints on models imposed by a 5 micro G cluster field and find a limited class of models that are compatible with this constraint. We also investigate the possibility that the excess hard (40-60 keV) X-ray emission in the cluster is produced by inverse Compton emission with the same electron population that produces the EUV excess. We find no scenarios that are compatible with a large cluster magnetic field, and consequently in this case these two components must be unrelated.

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Ming Yann Tsay, Chorng-Yuan Hwang, Stuart Bowyer. 2001-11-05. Constraints Imposed by a High Magnetic Field on Models for the EUV Emission in the Coma Cluster. https://arxiv.org/abs/astro-ph/0111072

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