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Lookup NU author(s): Dr Luiz Felippe Rodrigues,
Dr Luke Chamandy,
Professor Anvar Shukurov
This is the authors' accepted manuscript of an article that has been published in its final definitive form by Oxford University Press, 2019.
For re-use rights please refer to the publisher's terms and conditions.
We study the cosmic evolution of the magnetic fields of a large sample of spiral galaxies in a cosmologically representative volume by employing a semi-analytic galaxy formation model and numerical dynamo solver in tandem. We start by deriving time- and radius-dependent galaxy properties using the galform galaxy formation model, which are then fed into the nonlinear mean-field dynamo equations. These are solved to give the large-scale (mean) field as a function of time and galactocentric radius for a thin disc, assuming axial symmetry. A simple prescription for the evolution of the small-scale (random) magnetic field component is also adopted. We find that, while most massive galaxies are predicted to have large-scale magnetic fields at redshift z=0, a significant fraction of them are expected to contain negligible large-scale field. Our model indicates that, for most of the galaxies containing large-scale magnetic fields today, the mean-field dynamo becomes active at z<3. We compute the radial profiles of pitch angle, and find broad agreement with observational data for nearby galaxies.
Author(s): Rodrigues LFS, Chamandy L, Shukurov A, Baugh CM, Taylor AR
Publication type: Article
Publication status: Published
Journal: Monthly Notices of the Royal Astronomical Society
Print publication date: 21/02/2019
Online publication date: 30/11/2018
Acceptance date: 28/11/2018
Date deposited: 28/01/2019
ISSN (print): 0035-8711
ISSN (electronic): 1365-2966
Publisher: Oxford University Press
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