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We study transverse fast magnetohydrodynamic waves in a system of two coronal loops modeled as smoothed, dense plasma cylinders in a uniform magnetic field. The collective oscillatory properties of the system due to the interaction between…

Astrophysics · Physics 2009-11-13 M. Luna , J. Terradas , R. Oliver , J. L. Ballester

We investigate the behaviour of nonlinear, nonideal Alfv\'en wave propagation within an inhomogeneous magnetic environment. The governing MHD equations are solved in 1D and 2D using both analytical techniques and numerical simulations. We…

Solar and Stellar Astrophysics · Physics 2015-03-18 J. A. McLaughlin , I. De Moortel , A. W. Hood

Transverse MHD waves permeate the solar atmosphere and are a candidate for coronal heating. However, the origin of these waves is still unclear. In this work, we analyse coordinated observations from \textit{Hinode}/SOT and \textit{IRIS} of…

Solar and Stellar Astrophysics · Physics 2018-07-25 Patrick Antolin , Paolo Pagano , Ineke De Moortel , Valery M. Nakariakov

Observed spectral profiles of emission lines from the corona are found to have widths exceeding the thermal line width. To investigate the physical mechanism, we run a 3D MHD model of a single, straightened loop in which we partially…

Solar and Stellar Astrophysics · Physics 2024-04-02 C. A. Breu , H. Peter , S. K. Solanki , R. Cameron , I. De Moortel

We investigated travelling waves appearing as the primary pattern-forming instability in the nematic Phase 5 (Merck) in the planar geometry in order to test the recently developed weak electrolyte model of ac-driven electroconvection [M.…

patt-sol · Physics 2009-10-30 Martin Treiber , Nandor Eber , Agnes Buka , Lorenz Kramer

One candidate-model for heating the solar corona is magnetic reconnection that embodies Ohmic dissipation of current sheets. When numerous small-scaled magnetic reconnection occur, then it is possible to heat the corona. Due to the…

Solar and Stellar Astrophysics · Physics 2018-09-19 Charalambos Kanella , Boris V. Gudiksen

Coronal active regions are observed to get fuzzier and fuzzier (i.e. more and more confused and uniform) in harder and harder energy bands or lines. We explain this evidence as due to the fine multi-temperature structure of coronal loops.…

Solar and Stellar Astrophysics · Physics 2015-05-19 Massimiliano Guarrasi , Fabio Reale , Giovanni Peres

Longitudinal intensity oscillations along coronal loops that are interpreted as signatures of magneto-acoustic waves are observed frequently in different coronal structures. The aim of this paper is to estimate the physical parameters of…

Solar and Stellar Astrophysics · Physics 2016-04-13 A. Abedini

There is ample evidence of twisted magnetic structures in the solar corona. This motivates us to consider the magnetic twist as the cause of Alfven frequency continuum in the coronal loops, which can support the resonant absorption as a…

Solar and Stellar Astrophysics · Physics 2016-08-18 Zanyar Ebrahimi , Kayoomars Karami

Recent numerical investigations of wave propagation near coronal magnetic null points (McLaughlin and Hood: Astron. Astrophys. 459, 641,2006) have indicated how a fast MHD wave partially converts into a slow MHD wave as the disturbance…

Astrophysics · Physics 2008-08-01 A. M. D. McDougall , A. W. Hood

The expansion of coronal loops in the transition region may considerably influence the diagnostics of the plasma emission measure. The cross sectional area of the loops is expected to depend on the temperature and pressure, and might be…

Solar and Stellar Astrophysics · Physics 2015-06-18 M. Guarrasi , F. Reale , S. Orlando , A. Mignone , J. A. Klimchuk

The nanoflare paradigm of coronal heating has proven extremely promising for explaining the presence of hot, multi-million degree loops in the solar corona. In this paradigm, localized heating events supply enough energy to heat the solar…

Solar and Stellar Astrophysics · Physics 2020-09-02 Kalman J. Knizhnik , Will T. Barnes , Jeffrey W. Reep , Vadim M. Uritsky

Decayless kink oscillations are frequently observed in solar coronal loops and are considered potential contributors to coronal heating. Despite the ubiquity of this wave phenomenon, its driving mechanism remains unclear. Studies to derive…

Solar and Stellar Astrophysics · Physics 2026-03-04 Sudip Mandal , Cosima Breu , Hardi Peter

It has been found that the Kelvin-Helmholtz instability (KHI) induced by both transverse and torsional oscillations in coronal loops can reinforce the effects of wave heating. In this study, we model a coronal loop as a system of individual…

Solar and Stellar Astrophysics · Physics 2019-09-25 Mingzhe Guo , Tom Van Doorsselaere , Konstantinos Karampelas , Bo Li

Current analytical and numerical modelling suggest the existence of ubiquitous thin current sheets in the corona that could explain the observed heating requirements. On the other hand, new high resolution observations of the corona…

Solar and Stellar Astrophysics · Physics 2015-06-19 P. Antolin , T. Yokoyama , T. Van Doorsselaere

Results from 2.5D and 3D studies of the onset and development of the tearing instability are presented, using high fidelity resistive MHD simulations. A limited parameter study of the strength of the reconnecting field (or shear angle) was…

Solar and Stellar Astrophysics · Physics 2022-03-30 Lars K. S. Daldorff , James E. Leake , James A. Klimchuk

The Parker or field line tangling model of coronal heating is studied comprehensively via long-time high-resolution simulations of the dynamics of a coronal loop in cartesian geometry within the framework of reduced magnetohydrodynamics…

Astrophysics · Physics 2009-12-06 A. F. Rappazzo , M. Velli , G. Einaudi , R. B. Dahlburg

Propagating disturbances are often observed in active region fan-like coronal loops. They were thought to be due to slow mode MHD waves based on some of the observed properties. But the recent studies involving spectroscopy indicate that…

Solar and Stellar Astrophysics · Physics 2015-11-11 S. Mandal , T. Samanta , D. Banerjee , S. Krishna Prasad , L. Teriaca

We report on the first direct observation of a fast-mode wave propagating along and perpendicular to cool (171 {\AA}) arcade loops observed by the SDO/AIA. The wave was associated with an impulsive/compact flare, near the edge of a sunspot.…

Solar and Stellar Astrophysics · Physics 2015-06-24 Pankaj Kumar , D. E. Innes

One of the proposed damping mechanisms of coronal (transverse) loop oscillations in the kink-mode is resonant absorption as a result of the Alfven speed variation at the outer boundary of coronal loops. Analytical expressions for the period…