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Context: The majority of studies on stressed 3D magnetic null points consider magnetic reconnection driven by an external perturbation, but the formation of a genuine current sheet equilibrium remains poorly understood. This problem has…

Solar and Stellar Astrophysics · Physics 2012-09-07 Jorge Fuentes-Fernandez , Clare E. Parnell

We provide a valid magnetohydrostatic equilibrium from the collapse of a 2D X-point in the presence of a finite plasma pressure, in which the current density is not simply concentrated in an infinitesimally thin, one-dimensional current…

Solar and Stellar Astrophysics · Physics 2013-09-13 Jorge Fuentes-Fernández , Clare E. Parnell , Alan W. Hood

Three-dimensional null points are present in abundance in the solar corona, and the same is likely to be true in other astrophysical environments. Recent studies suggest that reconnection at such 3D nulls may play an important role in the…

Solar and Stellar Astrophysics · Physics 2011-09-28 D. I. Pontin , A. K. Al-Hachami , K. Galsgaard

The behaviour of magnetic perturbations of an initially potential three-dimensional equilibrium magnetic null point are investigated. The basic components which constitute a typical disturbance are taken to be rotations and shears, in line…

Astrophysics · Physics 2008-11-26 D. I. Pontin , K. Galsgaard

Context. We investigate the dynamical evolution of the reconnection process at an initially linear 3D null point that is stressed by a localised shear motion across the spine axis. The fan plane is not rotationally symmetric and this allows…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Klaus Galsgaard , David Pontin

The performed magnetohydrodynamic simulation examines the importance of magnetofluid evolution which naturally leads to current sheets in the presence of three-dimensional (3D) magnetic nulls. Initial magnetic field is constructed by…

Solar and Stellar Astrophysics · Physics 2017-06-20 Sanjay Kumar , R. Bhattacharyya

Recent advances in theory and computational experiments have shown the need to refine the previous categorisation of magnetic reconnection at three-dimensional null points -- points at which the magnetic field vanishes. We propose here a…

Solar and Stellar Astrophysics · Physics 2016-09-08 E. R. Priest , D. I. Pontin

To systematically stress a rotationally symmetric 3D magnetic null point by advecting the opposite footpoints of the spine axis in opposite directions. This stress eventually concentrates in the vicinity of the null point forming a local…

Solar and Stellar Astrophysics · Physics 2015-05-27 K. Galsgaard , D. I. Pontin

The nature of current sheet formation in the vicinity of three-dimensional (3D) magnetic null points is investigated. The particular focus is upon the effect of the compressibility of the plasma on the qualitative and quantitative…

Plasma Physics · Physics 2009-11-13 D. I. Pontin , A. Bhattacharjee , K. Galsgaard

Null collapse is an implosive process whereby MHD waves focus their energy in the vicinity of a null point, forming a current sheet and initiating magnetic reconnection. We consider, for the first time, the case of collapsing 3D magnetic…

Solar and Stellar Astrophysics · Physics 2018-03-21 J. O. Thurgood , D. I. Pontin , J. A. McLaughlin

The aim of this paper is to investigate the properties of magnetic reconnection at a 3D null point, with respect to their dependence on the symmetry of the magnetic field around the null. In particular we examine the rate of flux transport…

Solar and Stellar Astrophysics · Physics 2015-05-14 A. K. Al-Hachami , D. I. Pontin

Asymmetric current sheets are likely to be prevalent in both astrophysical and laboratory plasmas with complex three dimensional (3D) magnetic topologies. This work presents kinematic analytical models for spine and fan reconnection at a…

Plasma Physics · Physics 2013-06-28 Peter F Wyper , Rekha Jain

This work conducts a three-dimensional (3D), nonlinear magnetohydrodynamic (MHD) simulation to investigate wave generating, time-dependent reconnection around a magnetic null point. A non-periodic perturbation (in the $xz$-plane) triggers…

Solar and Stellar Astrophysics · Physics 2026-01-30 Luiz A. C. A. Schiavo , Gert J. J. Botha , James A. McLaughlin

Three-dimensional (3D) magnetic nulls are abundant in the solar atmosphere, as been firmly established through contemporary observations. They are established to be important magnetic structures in, for example, jets and circular ribbon…

Solar and Stellar Astrophysics · Physics 2024-06-11 Yogesh Kumar Maurya , Ramit Bhattacharyya , David I. Pontin , Sanjay Kumar

The open problem of how singular current structures form in line-tied, three-dimensional magnetic fields is addressed. A Lagrangian magneto-frictional relaxation method is employed to model the field evolution towards the final…

Solar and Stellar Astrophysics · Physics 2014-10-27 I. J. D. Craig , Frederic Effenberger

The nature of the evolution of the magnetic field, and of current sheet formation, at three-dimensional (3D) magnetic null points is investigated. A kinematic example is presented which demonstrates that for certain evolutions of a 3D null…

Astrophysics · Physics 2009-11-13 D. I. Pontin , A. Bhattacharjee , K. Galsgaard

The appearance of eruptive space plasma processes, e.g., in eruptive flares as observed in the solar atmosphere, is usually assumed to be caused by magnetic reconnection. The process of magnetic reconnection is often connected with singular…

Solar and Stellar Astrophysics · Physics 2009-09-07 Dieter Nickeler , Marian Karlicky , Miroslav Barta

Context. For the last thirty years, most of the studies on the relaxation of stressed magnetic fields in the solar environment have onlyconsidered the Lorentz force, neglecting plasma contributions, and therefore, limiting every equilibrium…

Solar and Stellar Astrophysics · Physics 2011-10-25 Jorge Fuentes-Fernández , Clare E. Parnell , Alan W. Hood

The magnetohydrodynamics of active region NOAA 11283 is simulated using an initial non-force-free magnetic field extrapolated from its photospheric vector magnetogram. We focus on the magnetic reconnections at a magnetic null point that…

Solar and Stellar Astrophysics · Physics 2020-11-11 Avijeet Prasad , Karin Dissauer , Qiang Hu , R. Bhattacharyya , Astrid M. Veronig , Sanjay Kumar , Bhuwan Joshi

This paper considers the current distributions that derive from finite amplitude perturbations of line-tied magnetic fields comprising hyperbolic field structures. The initial equilibrium on which we principally focus is a planar magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-19 I. J. D. Craig , D. I. Pontin
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