The First Magnetic Fields

• DOI: 10.1007/s11214-011-9833-5
• Publication Date: 2011-10-06T15:14:36Z
• Authors: Lawrence M. Widrow; Dongsu Ryu; Dominik R. G. Sch...; Kandaswamy Subram...; Christos G. Tsagas; Rudolf A. Treumann
• Keywords: High Energy Astrophysical Phenomena (astro-ph.HE); Quark-hadron transition; Cosmology and Nongalactic Astrophysics (astro-ph.CO); Magnetic fields; 539; FOS: Physical sciences; Astrophysics - High Energy Astrophysical Phenomena; Early Universe; Inflation; 7. Clean energy; 520; Astrophysics - Cosmology and Nongalactic Astrophysics

We review current ideas on the origin of galactic and extragalactic magnetic fields. We begin by summarizing observations of magnetic fields at cosmological redshifts and on cosmological scales. These observations translate into constraints on the strength and scale magnetic fields must have during the early stages of galaxy formation in order to seed the galactic dynamo. We examine mechanisms for the generation of magnetic fields that operate prior during inflation and during subsequent phase transitions such as electroweak symmetry breaking and the quark-hadron phase transition. The implications of strong primordial magnetic fields for the reionization epoch as well as the first generation of stars is discussed in detail. The exotic, early-Universe mechanisms are contrasted with astrophysical processes that generate fields after recombination. For example, a Biermann-type battery can operate in a proto-galaxy during the early stages of structure formation. Moreover, magnetic fields in either an early generation of stars or active galactic nuclei can be dispersed into the intergalactic medium.<br/>Accepted for publication in Space Science Reviews. Pdf can be also downloaded from http://canopus.cnu.ac.kr/ryu/cosmic-mag1.pdf<br/>