Nonlinear magnetic diffusion and magnetic helicity transport in galactic dynamos

N. Kleeorin, D. Moss, I. Rogachevskii, D. Sokoloff

Research output: Contribution to journalArticlepeer-review

38 Scopus citations

Abstract

We have extended our previous mean-field galactic dynamo model which included algebraic and dynamic alpha nonlinearities (Kleeorin et al. 2002), to include also a quenching of the turbulent diffusivity. We readily obtain equilibrium states for the large-scale magnetic field in the local disc dynamo model, and these fields have strengths that are comparable to the equipartition field strength. We find that the algebraic nonlinearity alone (i.e. quenching of both the α effect and turbulent magnetic diffusion) cannot saturate the growth of the mean magnetic field; only the combined effect of algebraic and dynamic nonlinearities can limit the growth of the mean magnetic field. However, in contrast to our earlier work without quenching of the turbulent diffusivity, we cannot now find satisfactory solutions in the no-z approximation to the axisymmetric galactic dynamo problem.

Original languageEnglish
Pages (from-to)9-18
Number of pages10
JournalAstronomy and Astrophysics
Volume400
Issue number1
DOIs
StatePublished - 1 Jan 2003

Keywords

  • Galaxies: Magnetic fields

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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