Gourgouliatos, KN and Hollerbach, R (2016) Resistive Tearing Instability in Electron-MHD: Application to Neutron Star Crusts. Monthly Notices of the Royal Astronomical Society, 463 (3). pp. 3381-3389. ISSN 0035-8711
Abstract
We study a resistive tearing instability developing in a system evolving through the combined effect of Hall drift in the Electron-MHD limit and Ohmic dissipation. We explore first the exponential growth of the instability in the linear case and we find the fastest growing mode,
the corresponding eigenvalues and dispersion relation. The instability growth rate scales as γ ∝ B2/3σ−1/3 where B is the magnetic field and σ the electrical conductivity. We confirm the development of the tearing resistive instability in the fully non-linear case, in a plane parallel
configuration where the magnetic field polarity reverses, through simulations of systems initiating in Hall equilibrium with some superimposed perturbation. Following a transient phase, during which there is some minor rearrangement of the magnetic field, the perturbation grows exponentially. Once the instability is fully developed the magnetic field forms the characteristic islands and X-type reconnection points, where Ohmic decay is enhanced. We discuss the implications of this instability for the local magnetic field evolution in neutron stars’ crusts,
proposing that it can contribute to heating near the surface of the star, as suggested by models of magnetar post-burst cooling. In particular, we find that a current sheet a few meters thick, covering as little as 1% of the total surface can provide 1042 erg in thermal energy within a
few days. We briefly discuss applications of this instability in other systems where the Hall effect operates such as protoplanetary discs and space plasmas.
Metadata
Item Type: | Article |
---|---|
Authors/Creators: |
|
Copyright, Publisher and Additional Information: | © 2016 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. |
Keywords: | stars: neutron, magnetars, methods: numerical, MHD, magnetic fields |
Dates: |
|
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: | 13 Sep 2016 13:49 |
Last Modified: | 13 Mar 2020 17:08 |
Published Version: | https://doi.org/10.1093/mnras/stw2309 |
Status: | Published |
Publisher: | Oxford University Press |
Identification Number: | 10.1093/mnras/stw2309 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:104561 |