title: On the Role of the Turbulent Dynamo in the Evolution of Cosmic Magnetic Fields
creator: Schober, Jennifer
subject: 500
subject: 500 Natural sciences and mathematics
subject: 520
subject: 520 Astronomy and allied sciences
subject: 530
subject: 530 Physics
description: The aim of this work is to explore the origin of magnetic fields in the Universe. We claim that the turbulent or small-scale dynamo, which amplifies weak seed fields on short timescales in the presence of turbulence, plays an important role in the evolution of cosmic magnetic fields. The theoretical model for the turbulent dynamo is generalized for various astrophysical environments, with a focus on different turbulence spectra. We derive analytical solutions for the dynamo growth rate in the kinematic phase and discuss the subsequent non-linear evolution as well as saturation. In the history of the Universe turbulence is expected to be driven efficiently at the latest during the formation of the first stars and galaxies, where gravitational energy is converted into chaotic motions as the dark matter halos accrete gas from the environment. We model these processes semi-analytically and implement magnetic field amplification by a turbulent dynamo. Our results show that unordered magnetic fields, with strengths comparable to the ones in local galaxies, were already present in the primordial Universe. A potential observational test for magnetic fields in young galaxies is suggested to probe our proposed scenario for the evolution of cosmic magnetic fields.
date: 2014
type: Dissertation
type: info:eu-repo/semantics/doctoralThesis
type: NonPeerReviewed
format: application/pdf
identifier: https://archiv.ub.uni-heidelberg.de/volltextserverhttps://archiv.ub.uni-heidelberg.de/volltextserver/17679/1/Thesis_JenniferSchober.pdf
identifier: DOI:10.11588/heidok.00017679
identifier: urn:nbn:de:bsz:16-heidok-176794
identifier:   Schober, Jennifer  (2014) On the Role of the Turbulent Dynamo in the Evolution of Cosmic Magnetic Fields.  [Dissertation]     
relation: https://archiv.ub.uni-heidelberg.de/volltextserver/17679/
rights: info:eu-repo/semantics/openAccess
rights: http://archiv.ub.uni-heidelberg.de/volltextserver/help/license_urhg.html
language: eng