Gourgouliatos, KN, Wood, TS and Hollerbach, R (2016) Magnetic field evolution in magnetar crusts through three dimensional simulations. Proceedings of the National Academy of Sciences, 113 (15). pp. 3944-3949. ISSN 0027-8424
Abstract
Current models of magnetars require extremely strong magnetic fields to explain their observed quiescent and bursting emission, implying that the field strength within the star’s outer crust is orders of magnitude larger than the dipole component inferred from spindown measurements. This presents a serious challenge to theories of magnetic field generation in a proto-neutron star. Here, we present detailed modelling of the evolution of the magnetic field in the crust of a neutron star through 3-D simulations. We find that, in the plausible scenario of equipartition of energy between global-scale poloidal and toroidal magnetic components, magnetic instabilities transfer energy to non-axisymmetric, kilometre-sized magnetic features, in which the local field strength can greatly exceed that of the global-scale field. These intense small-scale magnetic features can induce high energy bursts through local crust yielding, and the localised enhancement of Ohmic heating can power the star’s persistent emission. Thus, the observed diversity in magnetar behaviour can be explained with mixed poloidal-toroidal fields of comparable energies.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) 2016, The Authors. This is an author produced version of a paper published in Proceedings of the National Academy of Sciences. Uploaded in accordance with the publisher's self-archiving policy. In order to comply with the publisher requirements the University does not require the author to sign a non-exclusive licence for this paper. |
Keywords: | neutron stars; magnetars; Magnetohydrodynamics; pulsars |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Mathematics (Leeds) > Applied Mathematics (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 04 Mar 2016 16:38 |
Last Modified: | 16 Jan 2018 12:53 |
Published Version: | http://dx.doi.org/10.1073/pnas.1522363113 |
Status: | Published |
Publisher: | National Academy of Sciences |
Identification Number: | 10.1073/pnas.1522363113 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:96073 |