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It is known from numerical simulations that thermal conduction along magnetic field lines plays an important role in the evolution of the kink instability in coronal loops. This study presents the observational signatures of the kink…

Solar and Stellar Astrophysics · Physics 2013-03-05 G. J. J. Botha , T. D. Arber , Abhishek K. Srivastava

The aim of this work is to investigate and characterise non-thermal particle behaviour in a three-dimensional (3D) magnetohydrodynamical (MHD) model of unstable multi-threaded flaring coronal loops. We have used a numerical scheme which…

Solar and Stellar Astrophysics · Physics 2018-03-21 J. Threlfall , A. W. Hood , P. K. Browning

It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…

Solar and Stellar Astrophysics · Physics 2022-11-02 James A. Klimchuk , Kalman J. Knizhnik , Vadim M. Uritsky

Adopting the MPI-AMRVAC code, we present a 2.5-dimensional magnetohydrodynamic (MHD) simulation, which includes thermal conduction and radiative cooling, to investigate the formation and evolution of the coronal rain phenomenon. We perform…

Solar and Stellar Astrophysics · Physics 2022-03-09 Xiaohong Li , Rony Keppens , Yuhao Zhou

Context: Relaxation theory offers a straightforward method for estimating the energy that is released when a magnetic field becomes unstable, as a result of continual convective driving. Aims: We present new results obtained from nonlinear…

Solar and Stellar Astrophysics · Physics 2015-06-12 Michael Bareford , Alan Hood , Philippa Browning

We study the magnetic field and current structure associated with a coronal loop. Through this we investigate to what extent the assumptions of a force-free magnetic field break down and where they might be justified. We analyse a 3D MHD…

Solar and Stellar Astrophysics · Physics 2017-12-05 Jörn Warnecke , Feng Chen , Sven Bingert , Hardi Peter

Coronal rain consists of cool and dense plasma condensations formed in coronal loops as a result of thermal instability. Previous numerical simulations of thermal instability and coronal rain formation have relied on artificially adding a…

Solar and Stellar Astrophysics · Physics 2020-07-08 P. Kohutova , P. Antolin , A. Popovas , M. Szydlarski , V. H. Hansteen

For the first time, we demonstrate how an MHD avalanche might occur in a multi-threaded coronal loop. Considering 23 non-potential magnetic threads within a loop, we use 3D MHD simulations to show that only one thread needs to be unstable…

Solar and Stellar Astrophysics · Physics 2016-01-27 A. W. Hood , P. J. Cargill , P. K. Browning , K. V. Tam

Magnetic flux tubes in the solar corona support a rich variety of transverse oscillations, which are theoretically interpreted as magnetohydrodynamic (MHD) modes with a fast and/or Alfv\'enic character. In the standard flux tube model made…

Solar and Stellar Astrophysics · Physics 2024-12-13 Roberto Soler , Andrew Hillier

MHD waves permeate the solar atmosphere and constitute potential coronal heating agents. Yet, the waves detected so far may be but a small subset of the true existing wave power. Detection is limited by instrumental constraints, but also by…

Solar and Stellar Astrophysics · Physics 2017-02-03 Patrick Antolin , Ineke De Moortel , Tom Van Doorsselaere , Takaaki Yokoyama

Magnetohydrodynamic (MHD) instabilities allow energy to be released from stressed magnetic fields, commonly modelled in cylindrical flux tubes linking parallel planes, but, more recently, also in curved arcades containing flux tubes with…

Solar and Stellar Astrophysics · Physics 2021-08-25 James Threlfall , Jack Reid , Alan Hood

Recent observations of reflected propagating and standing slow-mode waves in hot flaring coronal loops have spurred our investigation into their underlying excitation and damping mechanisms. To understand these processes, we conduct 2.5D…

Solar and Stellar Astrophysics · Physics 2024-04-01 Tongjiang Wang , Leon Ofman , Stephen J. Bradshaw

We present in this paper both a linear study and numerical relativistic MHD simulations of the non-resonant streaming instability occurring in the precursor of relativistic shocks. In the shock front restframe, we perform a linear analysis…

High Energy Astrophysical Phenomena · Physics 2015-06-15 F. Casse , A. Marcowith , R. Keppens

We present the first results of three-dimensional (3D) numerical magnetohydrodynamic (MHD) simulations of the onset of magnetic reconnection via the tearing instability in dynamically thinning current sheets in the solar corona. In all our…

Solar and Stellar Astrophysics · Physics 2024-06-10 James Leake , Lars Daldorff , James Klimchuk

We aim to study the standing fundamental kink mode of coronal loops in the nonlinear regime, investigating the changes in energy evolution in the cross-section and oscillation amplitude of the loop which are related to nonlinear effects, in…

Solar and Stellar Astrophysics · Physics 2016-11-02 N. Magyar , T. Van Doorsselaere

In preparation for an experimental study of magnetorotational instability (MRI) in liquid metal, we present non-ideal two-dimensional magnetohydrodynamic simulations of the nonlinear evolution of MRI in the experimental geometry. The…

Astrophysics · Physics 2009-11-13 Wei Liu , Jeremy Goodman , Hantao Ji

We present results from 3D visco-resistive magnetohydrodynamic (MHD) simulations of the emergence of a convection zone magnetic flux tube into a solar atmosphere containing a pre-existing dipole coronal field, which is orientated to…

Solar and Stellar Astrophysics · Physics 2015-06-17 James E. Leake , Mark G. Linton , Tibor Török

The force-free coronal loop model by Titov & D\'emoulin (1999} is found to be unstable with respect to the ideal kink mode, which suggests this instability as a mechanism for the initiation of flares. The long-wavelength ($m=1$) mode grows…

Astrophysics · Physics 2007-05-23 T. Toeroek , B. Kliem , V. S. Titov

We study dynamical consequences of the kink instability of a twisted coronal flux rope, using the force-free coronal loop model by Titov & D\'emoulin (1999) as the initial condition in ideal-MHD simulations. When a critical value of the…

Astrophysics · Physics 2007-05-23 B. Kliem , V. S. Titov , T. Toeroek

Any successful model of coronal loops must explain a number of observed properties. For warm (~ 1 MK) loops, these include: 1. excess density, 2. flat temperature profile, 3. super-hydrostatic scale height, 4. unstructured intensity…

Solar and Stellar Astrophysics · Physics 2014-11-20 J. A. Klimchuk , J. T. Karpen , S. K. Antiochos
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