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The driving and excitation mechanisms of decay-less kink oscillations in coronal loops remain under debate. We aim to quantify and provide simple observational constraints on the photospheric driving of oscillating coronal loops in a few…

A model interpreting variations of EUV brightness upward propagating in solar coronal loops as slow magnetoacoustic waves is developed. A loop is considered to have a non-zero plane inclination angle and offset of circular loop centre from…

Astrophysics · Physics 2009-11-07 D. Tsiklauri , V. M. Nakariakov

This paper separately evaluates the effects of inclination and asymmetry of solar coronal loops on the resonant absorption of kink magnetohydrodynamic (MHD) oscillations. We modelled a typical coronal loop by a straight and axisymmetric…

Solar and Stellar Astrophysics · Physics 2021-04-06 Sirwan Amiri , Kayoomars Karami , Zanyar Ebrahimi

The scale heights of stratification and the widths of steady solar coronal loops exhibit properties unexplained by standard theory: observed scale heights are often much greater than static theory predicts, while the nearly-constant widths…

Astrophysics · Physics 2008-11-26 Gordon Petrie

We construct magnetostatic models of coronal loops in which the thermodynamics of the loop is fully consistent with the shape and geometry of the loop. This is achieved by treating the loop as a thin, compact, magnetic fibril that is a…

Solar and Stellar Astrophysics · Physics 2015-06-16 Bradley W. Hindman , Rekha Jain

We consider local, stratified, numerical models of isothermal accretion disks. The novel feature of our treatment is that radial extent L_x and azimuthal extent L_y satisfy H << L_x, L_y << R, where H is the scale height and R is the local…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Xiaoyue Guan , Charles F. Gammie

We use a combination of analytical theory, numerical simulation, and data analysis to study the propagation of acoustic waves along coronal loops. We show that the intensity perturbation of a wave depends on a number of factors, including…

Astrophysics · Physics 2009-11-10 J. A. Klimchuk , S. E. M. Tanner , I. De Moortel

Context. Transverse oscillations of coronal structures are currently intensively studied to explore the associated magnetohydrodynamic wave physics and perform seismology of the local medium. Aims. We make a first attempt to measure the…

Solar and Stellar Astrophysics · Physics 2020-07-01 C. R. Goddard , G. Nisticò

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…

We model a coronal loop as a three-dimensional magnetic cylinder in a realistic solar atmosphere that extends from the chromosphere to the corona. Kink oscillations, believed ubiquitous in the solar corona, are launched in the loop. Heating…

Solar and Stellar Astrophysics · Physics 2023-05-31 Mingzhe Guo , Timothy Duckenfield , Tom Van Doorsselaere , Konstantinos Karampelas , Gabriel Pelouze , Yuhang gao

We report on simulations of mildly turbulent convection in spherical wedge geometry with varying density stratification. We vary the density contrast within the convection zone by a factor of 20 and study the influence of rotation on the…

Solar and Stellar Astrophysics · Physics 2012-04-25 P. J. Käpylä , M. J. Mantere , A. Brandenburg

Recent observations show a variety of oscillation modes in the corona. Early non-imaging observations in radio wavelengths showed a number of fast-period oscillations in the order of seconds, which have been interpreted as fast sausage mode…

Astrophysics · Physics 2007-05-23 Markus J. Aschwanden

We examine resonantly damped kink modes in straight coronal slabs, paying special attention to the effects of the formulation for the transverse density distribution ("profile"). We work in the framework of pressure-less, gravity-free,…

Solar and Stellar Astrophysics · Physics 2021-06-23 Hui Yu , Bo Li , Shaoxia Chen , Mingzhe Guo

In recent years, coronal loops have been the focus of studies related to the damping of different magnetohydrodynamic (MHD) surface waves and their connection with coronal seismology and wave heating. For a better understanding of wave…

Solar and Stellar Astrophysics · Physics 2019-03-06 K. Karampelas , T. Van Doorsselaere , M. Guo

The P1/P2 period ratio of transversal loop oscillations is currently used for the diagnostics of longitudinal structuring of coronal loops as its deviation from 2 is intrinsically connected to the density scale-height along coronal loops…

Solar and Stellar Astrophysics · Physics 2011-11-22 B. Orza , I. Ballai , R. Jain , K. Murawski

Analyses of recent helioseismic data have produced ample evidence for substantial dynamical variation of the differential rotation within the solar convection zone. Given the inevitable difficulties in resolving the precise nature of…

Astrophysics · Physics 2009-11-10 Eurico Covas , David Moss , Reza Tavakol

Magnetohydrodynamic (MHD) kink waves have been observed frequently in solar coronal flux tubes, which makes them a great tool for seismology of the solar corona. Here, the effect of viscosity is studied on the evolution of kink waves. To…

Solar and Stellar Astrophysics · Physics 2020-05-12 Zanyar Ebrahimi , Roberto Soler , Kayoomars Karami

Context. Stars experience rapid contraction or expansion at different phases of their evolution. Modelling the angular momentum and chemical elements transport occurring during these phases remains an unsolved problem. Aims. We study a…

Solar and Stellar Astrophysics · Physics 2021-05-05 B. Gouhier , F. Lignières , L. Jouve

Recent observations have revealed the ubiquitous presence of magnetohydrodynamic (MHD) waves and oscillations in the solar corona. The aim of this review is to present recent progress in the observational study of four types of wave (or…

Solar and Stellar Astrophysics · Physics 2018-04-02 Tongjiang Wang

The propagation and the evolution of Alfvenic pulses in the solar coronal arcades is investigated by means of MHD numerical simulations. Significant transverse oscillations in coronal loops, triggered by nearby flare events, are often…

Astrophysics · Physics 2009-11-10 Luca Del Zanna , Eveline Schaekens , Marco Velli