The Origin of Magnetic Fields in Galaxies

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 $\sim 0.034\mu G$ fields over $\sim 0.3$ kpc regions in galaxies. If the dipole magnetic fields predicted by the Fluctuation-Dissipation-Theorem are not completely random, microgauss fields over regions $\gtrsim 0.34$ kpc are easily obtained. The model is thus a strong candidate for resolving the problem of the origin of magnetic fields in $\lesssim 10^9$ years in high redshift galaxies.

10 pages, 3 figures

References in corpus (8)

• Turbulence and Magnetic Fields in the Large Scale Structure of the Universe
• On the Origin of Cosmic Magnetic Fields
• Evolution of magnetic fields in galaxies and future observational tests with the Square Kilometre Array
• Cosmological Magnetic Field: a fossil of density perturbations in the early universe
• Reionization - A probe for the stellar population and the physics of the early universe
• Constraints on the Evolution of the Primordial Magnetic Field from the Small-Scale Cosmic Microwave Background Angular Anisotropy
• Primordial magnetic fields from second-order cosmological perturbations: Tight coupling approximation
• The Origin of Primordial Magnetic Fields

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• Magnetic fields in primordial accretion disks
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• Theoretical Estimates of 2-point Shear Correlation Functions Using Tangled Magnetic Field Power Spectrum
• Supernova explosions in magnetized, primordial dark matter halos
• Random Primordial Magnetic Fields and the Gas Content of Dark Matter Halos
• Magnetic braking during direct collapse black hole formation
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