Amplification of Magnetic Fields in the Centers of Cluster Cooling Flows
In 1990, Soker & Sarazin predicted that cooling flows in clusters of galaxies would compress ambient intracluster magnetic fields until the magnetic pressure becomes comparable to the local thermal pressure. Strong, centrally enhanced magnetic fields were subsequently detected through Faraday rotation measurements of cooling-flow clusters. This compression of the magnetic field is one of the strongest circumstantial indicators of "flow" in cluster cooling flows. We present two additional mechanisms by which rotating cooling flows can generate strong, centrally enhanced magnetic fields: through the twisting of magnetic flux tubes and/or the operation of a fast α-ω dynamo. This will lead to strong, and possibly violent, magnetic activity in the inner ~10 kpc of cooling-flow clusters. Such magnetic activity, e.g., reconnection, can generate turbulence, heat, and relativistic particles, which can power the optical filaments that are observed within this spatial scale in many cooling flows and can form diffuse radio emission in the same region.
|Other Authors:||Patrick Godon, Noam Soker, Raymond E. White|