Magnetic reconnection is believed to be the driver of many explosive phenomena in Astrophysics, from solar to gamma-ray flares in magnetars and in the Crab nebula. However, reconnection rates from classic MHD models are far too slow to explain such observations. Recently, it was realized that when a current sheet gets sufficiently thin, the reconnection rate of the tearing instability becomes "ideal", in the sense that the current sheet destabilizes on the "macroscopic" Alfvenic timescales, regardless of the Lundquist number of the plasma. Here we present 2D compressible MHD simulations in the classical, Hall, and relativistic regimes. In particular, the onset of secondary tearing instabilities is investigated within Hall-MHD for the first time. In the frame of relativistic MHD, we summarize the main results from Del Zanna et al. [1]: the relativistic tearing instability is found to be extremely fast, with reconnection rates of the order of the inverse of the light crossing time, as required to explain the high-energy explosive phenomena. © 2018 Institute of Physics Publishing. All rights reserved.

Fast magnetic reconnection: The ideal tearing instability in classic, Hall, and relativistic plasmas / Papini, E.; Landi, S.; Del Zanna, L.. - In: JOURNAL OF PHYSICS. CONFERENCE SERIES. - ISSN 1742-6588. - ELETTRONICO. - 1031:(2018), pp. 0-0. (Intervento presentato al convegno 12th International Conference on Numerical Modeling of Space Plasma Flows, ASTRONUM 2017 tenutosi a France nel 2017) [10.1088/1742-6596/1031/1/012020].

Fast magnetic reconnection: The ideal tearing instability in classic, Hall, and relativistic plasmas

Papini, E.
Membro del Collaboration Group
;
Landi, S.
Membro del Collaboration Group
;
Del Zanna, L.
Membro del Collaboration Group
2018

Abstract

Magnetic reconnection is believed to be the driver of many explosive phenomena in Astrophysics, from solar to gamma-ray flares in magnetars and in the Crab nebula. However, reconnection rates from classic MHD models are far too slow to explain such observations. Recently, it was realized that when a current sheet gets sufficiently thin, the reconnection rate of the tearing instability becomes "ideal", in the sense that the current sheet destabilizes on the "macroscopic" Alfvenic timescales, regardless of the Lundquist number of the plasma. Here we present 2D compressible MHD simulations in the classical, Hall, and relativistic regimes. In particular, the onset of secondary tearing instabilities is investigated within Hall-MHD for the first time. In the frame of relativistic MHD, we summarize the main results from Del Zanna et al. [1]: the relativistic tearing instability is found to be extremely fast, with reconnection rates of the order of the inverse of the light crossing time, as required to explain the high-energy explosive phenomena. © 2018 Institute of Physics Publishing. All rights reserved.
2018
Journal of Physics: Conference Series
12th International Conference on Numerical Modeling of Space Plasma Flows, ASTRONUM 2017
France
2017
Papini, E.; Landi, S.; Del Zanna, L.
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Utilizza questo identificatore per citare o creare un link a questa risorsa: https://hdl.handle.net/2158/1142346
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