Lyutikov, M, Sironi, L, Komissarov, SS et al. (1 more author) (2017) Explosive X-point collapse in relativistic magnetically dominated plasma. Journal of Plasma Physics, 83 (6). 635830601. ISSN 0022-3778
Abstract
The extreme properties of the gamma-ray flares in the Crab nebula present a clear challenge to our ideas on the nature of particle acceleration in relativistic astrophysical plasma. It seems highly unlikely that standard mechanisms of stochastic type are at work here and hence the attention of theorists has switched to linear acceleration in magnetic reconnection events. In this series of papers, we attempt to develop a theory of explosive magnetic reconnection in highly magnetized relativistic plasma which can explain the extreme parameters of the Crab flares. In the first paper, we focus on the properties of the X-point collapse. Using analytical and numerical methods (fluid and particle-in-cell simulations) we extend Syrovatsky’s classical model of such collapse to the relativistic regime. We find that the collapse can lead to the reconnection rate approaching the speed of light on macroscopic scales. During the collapse, the plasma particles are accelerated by charge-starved electric fields, which can reach (and even exceed) values of the local magnetic field. The explosive stage of reconnection produces non-thermal power-law tails with slopes that depend on the average magnetization σ. For sufficiently high magnetizations and vanishing guide field, the non-thermal particle spectrum consists of two components: a low-energy population with soft spectrum that dominates the number census; and a high-energy population with hard spectrum that possesses all the properties needed to explain the Crab flares.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | (c) Cambridge University Press 2017. This article has been published in a revised form in Journal of Plasma Physics https://doi.org/10.1017/S0022377817000629 This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. |
Keywords: | magnetized plasmas; plasma nonlinear phenomena; space plasma physics |
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) |
Funding Information: | Funder Grant number Science & Technology Facilities Council (STFC) ST/K000853/1 |
Depositing User: | Symplectic Publications |
Date Deposited: | 30 May 2018 13:48 |
Last Modified: | 29 Apr 2019 15:41 |
Status: | Published |
Publisher: | Cambridge University Press |
Identification Number: | 10.1017/S0022377817000629 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:131336 |