Origin of magnetic fields in galaxies

2009/10/31 by Rafael S. de Souza, R. Opher
Physics and Astronomy · #Astrophysics #Cosmology and Gravitation Theories #Dissipation #Galaxies: Formation, Evolution, Phenomena #Galaxy #Magnetic field #Physics #Quantum mechanics #Random field #Redshift #Solar and Space Plasma Dynamics #Universe #astro-ph.CO #astro-ph.GA

paper · pdf · doi:10.1103/physrevd.81.067301

published as Phys.Rev.D81:067301,2010 · 10 pages, 3 figures

arxiv created 2010/02/24 · openalex publication_date 2010/03/10 · arxiv updated 2010/04/29 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05

Abstract

Microgauss magnetic fields are observed in all galaxies at low and high redshifts. The origin of these intense magnetic fields is a challenging question in astrophysics. We show here that the natural plasma fluctuations in the primordial Universe (assumed to be random), predicted by the fluctuation -dissipation theorem, predicts \ensuremath∼0.034 \ensuremathμG fields over \ensuremath∼0.3 kpc regions in galaxies. If the dipole magnetic fields predicted by the fluctuation-dissipation theorem are not completely random, microgauss fields over regions \ensuremath\gtrsim0.34 kpc are easily obtained. The model is thus a strong candidate for resolving the problem of the origin of magnetic fields in \ensuremath\lesssim10⁹ years in high redshift galaxies.

Citations

• Cosmological Magnetic Field: A Fossil of Density Perturbations in the Early Universe
• Statistical-Mechanical Theory of Irreversible Processes. I. General Theory and Simple Applications to Magnetic and Conduction Problems
• Spectra and Growth Rates of Fluctuating Magnetic Fields in the Kinematic Dynamo Theory with Large Magnetic Prandtl Numbers
• Turbulence and Magnetic Fields in the Large-Scale Structure of the Universe