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Related papers: Slow and sausage loop mode excitation due to local…

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We consider damping and absorption of solar $p$ modes due to their energy loss to magnetic tube waves that can freely carry energy out of the acoustic cavity. The coupling of $p$ modes and sausage tube waves is studied in a model atmosphere…

Solar and Stellar Astrophysics · Physics 2015-06-19 Andrew Gascoyne , Rekha Jain , Bradley Hindman

This letter explores the relevance of nanoflare based models for heating the quiet sun corona. Using metrewave data from the Murchison Widefield Array, we present the first successful detection of impulsive emissions down to flux densities…

Solar and Stellar Astrophysics · Physics 2021-02-25 Surajit Mondal , Divya Oberoi , Atul Mohan

A quantitative study of the observable radio signatures of the sausage, kink, and torsional MHD oscillation modes in flaring coronal loops is performed. Considering first non-zero order effect of these various MHD oscillation modes on the…

Solar and Stellar Astrophysics · Physics 2015-06-03 George Mossessian , Gregory D. Fleishman

Non-uniformity of the solar atmosphere along with the presence of non-adiabatic processes such as radiation cooling and unspecified heating can significantly affect the dynamics and properties of magnetoacoustic (MA) waves. To address the…

Solar and Stellar Astrophysics · Physics 2022-07-20 D. V. Agapova , S. A. Belov , N. E. Molevich , D. I. Zavershinskii

Working in pressureless magnetohydrodynamics, we examine the consequences of some peculiar dispersive properties of linear fast sausage modes (FSMs) in one-dimensional cylindrical equilibria with a continuous radial density profile…

Solar and Stellar Astrophysics · Physics 2022-03-30 Bo Li , Shao-Xia Chen , Ao-Long Li

Rapidly decaying slow magnetoacoustic waves are regularly observed in the solar coronal structures, offering a promising tool for a seismological diagnostics of the coronal plasma, including its thermodynamical properties. The effect of…

Solar and Stellar Astrophysics · Physics 2019-08-21 D. Y. Kolotkov , V. M. Nakariakov , D. I. Zavershinskii

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

By focusing on the oscillations of the cross-sectional area and the intensity of magnetic waveguides located in the lower solar atmosphere, we aim to detect and identify magnetohydrodynamic (MHD) sausage waves. Capturing several series of…

Solar and Stellar Astrophysics · Physics 2015-06-11 I. Dorotovic , R. Erdelyi , N. Freij , V. Karlovsky , I. Marquez

We present a study of the spatial and spectral evolution of the loop-top (LT) sources in a sample of 6 flares near the solar limb observed by {\it RHESSI}. A distinct coronal source, which we identify as the LT source, was seen in each of…

Astrophysics · Physics 2009-11-13 Yan Wei Jiang , Siming Liu , Wei Liu , Vahe Petrosian

We perform direct numerical simulations of an externally driven two-dimensional magnetohydrodynamic system over extended periods of time to simulate the dynamics of a transverse section of a solar coronal loop. A stationary and large-scale…

Astrophysics · Physics 2009-10-30 Pablo Dmitruk , Daniel O. Gomez

The back-reaction of the perturbed thermal equilibrium in the solar corona on compressive perturbations, also known as the effect of wave-induced thermal misbalance, is known to result in thermal instabilities chiefly responsible for the…

Solar and Stellar Astrophysics · Physics 2023-01-24 Dmitrii Y. Kolotkov , Valery M. Nakariakov , Joseph B. Fihosy

Twisted coronal loops in the solar atmosphere may become kink-unstable when their magnetic field lines are sufficiently twisted. This instability can trigger magnetic reconnection, leading to the emission of electromagnetic radiation, which…

Solar and Stellar Astrophysics · Physics 2025-10-07 James Stewart , Philippa K. Browning , Mykola Gordovskyy

Standing long-period (with the periods longer than several minutes) oscillations in large hot (with the temperature higher than 3 MK) coronal loops have been observed as the quasi-periodic modulation of the EUV and microwave intensity…

Solar and Stellar Astrophysics · Physics 2016-06-15 Sanjay Kumar , V. M. Nakariakov , Y. -J. Moon

The nature and detailed properties of the heating of the million-degree solar corona are important issues that are still largely unresolved. Nanoflare heating might be dominant in active regions and quiet Sun, although direct signatures of…

Coronal flare emission is commonly observed to decay on timescales longer than those predicted by impulsively-driven, one-dimensional flare loop models. This discrepancy is most apparent during the gradual phase, where emission from these…

Solar and Stellar Astrophysics · Physics 2023-03-01 William Ashfield , Dana Longcope

We study the effect of localized sound-speed perturbations on global mode frequencies by applying techniques of global helioseismology on numerical simulations of the solar acoustic wave field. Extending the method of realization noise…

Astrophysics · Physics 2009-11-13 S. M. Hanasoge , T. P. Larson

Recent hydrodynamical simulations of convection in a solar-like model suggest that penetrative convective flows at the boundary of the convective envelope modify the thermal background in the overshooting layer. Based on these results, we…

Solar and Stellar Astrophysics · Physics 2022-03-14 Baraffe I , Constantino T , Clarke J , Le Saux A , Goffrey T , Guillet T , Pratt J , Vlaykov D. G

We studied long duration flare observed with Nobeyama Radioheliograph at frequencies 17 and 34 GHz and with Ramaty High Energy Solar Spectroscopic Imager at 25-50 keV. We found that microwave and hard X-ray emission variation contain…

Solar and Stellar Astrophysics · Physics 2011-10-07 Veronika Reznikova , Kiyoto Shibasaki

A possible key element for large-scale energy release in the solar corona is an MHD kink instability in a single twisted magnetic flux tube. An initial helical current sheet fragments in a turbulent way into smaller-scale sheets, similarly…

Solar and Stellar Astrophysics · Physics 2023-10-04 G. Cozzo , J. Reid , P. Pagano , F. Reale , A. W. Hood

Slow magnetoacoustic waves were first detected in hot ($>$6 MK) flare loops by the SOHO/SUMER spectrometer as Doppler shift oscillations in Fe XIX and Fe XXI lines. Recently, such longitudinal waves have been found by SDO/AIA in the 94 and…

Solar and Stellar Astrophysics · Physics 2017-01-11 Tongjiang Wang , Leon Ofman , Xudong Sun , Elena Provornikova , Joseph M. Davila