English
Related papers

Related papers: Twisted coronal loops in uniform gravity

200 papers

This present study deals with the dissipative instability that appears in a compressible partially ionised plasma slab embedded in a uniform magnetic field, modelling the state of the plasma in solar prominences. In the partially ionised…

Solar and Stellar Astrophysics · Physics 2018-02-28 J. F. Mather , I. Ballai , R. Erdelyi

The electromagnetic instabilities excited by the temperature anisotropy have been always one of the interesting issues in real high-density physical systems, where the relativistic and quantum effects due to spin can be important. This…

Plasma Physics · Physics 2017-11-21 M. Mahdavi , H. Khanzadeh

Magnetic reconnection can develop spontaneously via the tearing instability, often invoked to explain disruptive instabilities in fusion devices, solar flares, the generation of periodic density disturbances at the tip of helmet streamers,…

Plasma Physics · Physics 2026-03-04 Faisal Sayed , Anna Tenerani , Richard Fitzpatrick

The temperature of the solar atmosphere increases from thousands to millions of degrees moving from the lower layer (chromosphere) to the outermost one (corona), while the density drops accordingly. The mechanism behind this phenomenon,…

Solar and Stellar Astrophysics · Physics 2023-12-27 Luca Barbieri , Lapo Casetti , Andrea Verdini , Simone Landi

A large part of the hot corona consists of magnetically confined, bright plasma loops. These observed loops are in turn structured into bright strands. We investigate the relationship between magnetic field geometry, plasma properties and…

Solar and Stellar Astrophysics · Physics 2025-12-22 C. A. Breu , D. I. Pontin , E. Priest , I. De Moortel

Force-free extrapolations are widely used to study the magnetic field in the solar corona based on surface measurements. The extrapolations assume that the ratio of internal energy of the plasma to magnetic energy, the plasma-beta is…

Solar and Stellar Astrophysics · Physics 2015-11-25 H. Peter , J. Warnecke , L. P. Chitta , R. H. Cameron

Recent observations revealed that the solar atmosphere is highly structured in density, temperature and magnetic field. The presence of these gradients may lead to the appearance of currents in the plasma, which in the weakly collisional…

Astrophysics · Physics 2009-11-13 R. Mecheri , E. Marsch

Slow magnetoacoustic oscillations in stellar coronal loops with gravitational stratification are analyzed with a numerical solution of the boundary-value problem for eigenvalues and eigen functions. In this study, we only focus on the…

Solar and Stellar Astrophysics · Physics 2022-06-01 Daye Lim , Valery M. Nakariakov , Yong-Jae Moon

Solar coronal loops are commonly subject to oscillations. Observations of coronal oscillations are used to infer physical properties of the coronal plasma using coronal seismology. Excitation and evolution of oscillations in coronal loops…

Solar and Stellar Astrophysics · Physics 2021-03-17 P. Kohutova , A. Popovas

Aims. We aim to improve the understanding of the physical mechanisms behind the slower than free-fall motion and the two-stage evolution (an initial phase of acceleration followed by an almost constant velocity phase) detected in coronal…

Solar and Stellar Astrophysics · Physics 2020-02-05 David Martínez-Gómez , Ramón Oliver , Elena Khomenko , Manuel Collados

Non-linear force-free fields are the most general case of force-free fields, but the hardest to model as well. There are numerous methods of computing such fields by extrapolating vector magnetograms from the photosphere, but very few…

Solar and Stellar Astrophysics · Physics 2021-06-29 A. Malanushenko , D. W. Longcope , D. E. McKenzie

It is shown that a constant external magnetic field, generally speaking, is not able to prevent breaking (loss of smoothness) of relativistic plasma oscillations, even if they are arbitrarily small perturbations of the zero steady-state.…

Mathematical Physics · Physics 2022-06-08 Olga S. Rozanova

Observations and numerical simulations of laboratory and space plasmas in almost collisionless regimes reveal anisotropic and non-gyrotropic particle distribution functions. We investigate how such states can persist in the presence of a…

Plasma Physics · Physics 2015-08-19 S. S. Cerri , F. Pegoraro , F. Califano , D. Del Sarto , F. Jenko

We present numerical studies of the nonlinear, resistive magnetohydrodynamic (MHD) evolution of coronal loops. For these simulations we assume that the loops carry no net current, as might be expected if the loop had evolved due to vortex…

Astrophysics · Physics 2009-10-31 T. D. Arber , A. W. Longbottom , R. A. M. Van der Linden

Measurements of the relaxation of a zonal electrostatic potential perturbation in a non-axisymmetric magnetically confined plasma are presented. A sudden perturbation of the plasma equilibrium is induced by the injection of a cryogenic…

Magnetars are surrounded by diffuse plasma in magnetic field strengths well above the quantum electrodynamic critical value. We derive equations of "quantum force-free electrodynamics" for this plasma using effective field theory arguments.…

High Energy Astrophysical Phenomena · Physics 2016-05-25 Marat Freytsis , Samuel E. Gralla

We present the results of three-dimensional global magnetohydrodynamic (MHD) simulations of the Parker-shearing instability in a differentially rotating torus initially threaded by toroidal magnetic fields. An equilibrium model of…

Astrophysics · Physics 2009-10-31 M. Machida , MITSURU R. Hayashi , R. Matsumoto

[..] The change in the magnetic configuration due to the increase/decrease of electric current for different force-free models (potential, linear and nonlinear force-free fields) has never been studied in detail before. Here we focus…

Solar and Stellar Astrophysics · Physics 2015-05-28 S. Regnier

Using full three-dimensional magnetohydrodynamic numerical simulations, we study the effects of magnetic field sigmoidity or helicity on the properties of the fundamental kink oscillation of solar coronal loops. Our model consists of a…

Solar and Stellar Astrophysics · Physics 2020-05-20 N. Magyar , V. M. Nakariakov

We present numerical models from the field-aligned Hydrodynamics and Radiation Code (HYDRAD) of a highly asymmetric closed coronal loop with near-singular expansion factor. This loop was chosen to simulate a coronal magnetic flux tube that…

Solar and Stellar Astrophysics · Physics 2023-02-08 Emily I Mason , Spiro K Antiochos , Stephen Bradshaw