THE FAST GALACTIC DYNAMO
Abstract:The α-effect and the coefficient of eddy diffusivity are calculated for the magnetic field in a random flow with recovery. Such a flow loses its memory abruptly at random times that form a Poisson flow of events. Interstellar turbulence sustained by supernova outbursts is one of the physical realizations of such a flow. The growth rates and configurations of large-scale galactic magnetic fields for this situation are close to those predicted by simple galactic dynamo models. At the same time, the model of a flow with recovery makes it possible to trace the role of the effective "forgetting" of correlations. The presence of this forgetting distinguishes interstellar turbulence from other types of random flows.
Document Type: Research Article
Affiliations: Subdivision of Probability Theory, Department of Mechanics and Mathematics, Moscow State University, Moscow, 119899, Russia
Publication date: February 1, 2003