Magnetic field reversals and galactic dynamos

Abstract

We argue that global magnetic field reversals similar to those observed in the Milky Way occur quite frequently in mean-field galactic dynamo models that have relatively strong, random, seed magnetic fields that are localized in discrete regions. The number of reversals decreases to zero with reduction of the seed strength, efficiency of the galactic dynamo and size of the spots of the seed field. A systematic observational search for magnetic field reversals in a representative sample of spiral galaxies promises to give valuable information concerning seed magnetic fields and, in this way, to clarify the initial stages of galactic magnetic field evolution.

References in corpus (6)

• Deriving global structure of the Galactic Magnetic Field from Faraday Rotation Measures of extragalactic sources
• Modeling the Magnetic Field in the Galactic Disk using New Rotation Measure Observations from the Very Large Array
• Observational constraints on models for the interstellar magnetic field in the Galactic disk
• The Galactic distribution of magnetic fields in molecular clouds and HII regions
• Multiscale magnetic fields in spiral galaxies: evolution and reversals
• Cosmic Magnetic Fields: Observations and Prospects

Cited by in corpus (9)

• The magnetic field structure of the central region in M31
• The Complex Large-scale Magnetic Fields in the First Galactic Quadrant as Revealed by the Faraday Depth Profile Disparity
• The formation of regular interarm magnetic fields in spiral galaxies
• Enhancement of magnetic fields arising from galactic encounters
• Global enhancement and structure formation of the magnetic field in spiral galaxies
• Magnetic fields near the peripheries of galactic discs
• Superposing the Magnetic spiral structure of the Milky Way, on the stellar spiral arms -- Matching the unique galactic magnetic field reversal Zone with two galactic spiral arm Segments
• The Galactic Dynamo and Superbubbles
• Synthesizing Observations and Theory to Understand Galactic Magnetic Fields: Progress and Challenges