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Related papers: Solar flares and Kelvin-Helmholtz instabilities: A…

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Recent progress in solar Hard X-ray (HXR) observations with RHESSI data and methods for spectral inversion allow us to study model-independent mean electron flux spectra in solar flares. We report several hard X-ray events observed by…

Astrophysics · Physics 2009-11-11 Eduard P. Kontar , John C. Brown

We present two-dimensional (2D) particle-in-cell simulations of a magnetized, collisionless, relativistic pair plasma subjected to combined velocity and magnetic-field shear, a scenario typical at intermittent structures in plasma…

High Energy Astrophysical Phenomena · Physics 2025-10-27 Tsun Hin Navin Tsung , Gregory R. Werner , Dmitri A. Uzdensky , Mitchell C. Begelman

At hard X-ray energies, the bright footpoint emission from solar flare loops often prevents a detailed analysis of the weaker loop-top source morphology due to the limited dynamic range available for X-ray imaging. Here, we study the X1.3…

Solar and Stellar Astrophysics · Physics 2016-12-21 Frederic Effenberger , Fatima Rubio da Costa , Vahe Petrosian

Plasma turbulence is thought to be associated with various physical processes involved in solar flares, including magnetic reconnection, particle acceleration and transport. Using Ramaty High Energy Solar Spectroscopic Imager ({\it RHESSI})…

Solar and Stellar Astrophysics · Physics 2015-05-27 E. P. Kontar , I. G. Hannah , N. H. Bian

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

Cool ($\approx 10^4$K), dense material permeates the hot ($\approx 10^6$K), tenuous solar corona in form of coronal condensations, for example prominences and coronal rain. As the solar atmosphere evolves, turbulence can drive mixing…

Solar and Stellar Astrophysics · Physics 2025-01-22 Ben Snow , Chris Osborne , Andrew Hillier

Understanding the relationship among different emission components plays an essential role in the study of particle acceleration and energy conversion in solar flares. In flares where gradual and impulsive emission components can be readily…

Solar and Stellar Astrophysics · Physics 2015-06-15 Siming Liu , Youping Li , Lyndsay Fletcher

The conditions for the development of a Kelvin-Helmholtz Instability (KHI) for the Quark-gluon Plasma (QGP) flow in a peripheral heavy-ion collision is investigated. The projectile and target side particles are separated by an energetically…

Nuclear Theory · Physics 2013-02-22 D. J. Wang , Z. Néda , L. P. Csernai

We have investigated how the degree of imbalance in solar wind turbulence is modified by large-scale velocity shears in the solar wind plasma. The balance between counterpropagating Alfv\'enic fluctuations, which interact nonlinearly to…

Space Physics · Physics 2023-03-29 Juska E. Soljento , Simon W. Good , Adnane Osmane , Emilia K. J. Kilpua

In collision-poor plasmas from space, e.g., solar wind or stellar outflows, the heat-flux carried by the strahl or beaming electrons is expected to be regulated by the self-generated instabilities. Recently, simultaneous field and particle…

Plasma Physics · Physics 2019-09-05 R. A. López , S. M. Shaaban , M. Lazar , S. Poedts , P. H. Yoon , A. Micera , G. Lapenta

The Neupert effect refers to the strong correlation between the soft X-ray (SXR) light curve and the time-integrated hard X-rays (HXR) or microwave flux, which is frequently observed in solar flares. In this article, we therefore utilized…

Solar and Stellar Astrophysics · Physics 2024-04-04 Dong Li , Hanyang Dong , Wei Chen , Yang Su , Yu Huang , Zongjun Ning

Recent observations show cool, oscillating prominence threads fading when observed in cool spectral lines and appearing in warm spectral lines. A proposed mechanism to explain this evolution is that the threads were heated by turbulence…

Solar and Stellar Astrophysics · Physics 2020-01-08 Andrew Hillier , Inigo Arregui

We study the effects of Kelvin-Helmholtz instability (KHI) on the cold streams that feed high-redshift galaxies through their hot haloes, generalizing our earlier analyses of a 2D slab to a 3D cylinder, but still limiting our analysis to…

Astrophysics of Galaxies · Physics 2019-01-16 Nir Mandelker , Daisuke Nagai , Han Aung , Avishai Dekel , Dan Padnos , Yuval Birnboim

The Kelvin-Helmholtz instability (KHI) is a standard test of hydrodynamic and magnetohydrodynamic (MHD) simulation codes and finds many applications in astrophysics. The classic linear theory considers a discontinuity in density and…

Astrophysics of Galaxies · Physics 2019-02-13 Thomas Berlok , Christoph Pfrommer

We investigate the conditions under which the magnetohydrodynamic (MHD) modes in a cylindrical magnetic flux tube moving along its axis become unstable against the Kelvin--Helmholtz (KH) instability. We \textbf{use} the dispersion relations…

Solar and Stellar Astrophysics · Physics 2018-01-24 I. Zhelyazkov , Z. Dimitrov

Context: Solar flare hard X-rays (HXRs) are thought to be produced by nonthermal coronal electrons stopping in the chromosphere, or remaining trapped in the corona. The collisional thick target model (CTTM) predicts that sources produced by…

Solar and Stellar Astrophysics · Physics 2015-06-15 A. O'Flannagain , P. Gallagher , J. Brown , R. Milligan , G. Holman

Strong shear flow regions found in astrophysical jets are shown to be important dissipation regions, where the shear flow kinetic energy is converted into electric and magnetic field energy via shear instabilities. The emergence of these…

High Energy Astrophysical Phenomena · Physics 2014-04-03 E. P. Alves , T. Grismayer , R. A. Fonseca , L. O. Silva

We study Kelvin-Helmholtz (KH) instability at the interface of a disc and corona system by doing a linear perturbation analysis. The disc is assumed to be thin, however, the corona is considered to be nearly quasispherical because of its…

Astrophysics of Galaxies · Physics 2015-05-18 Mohsen Shadmehri , Perikles Rammos

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

Observational aspects of solar flares relevant to the acceleration process of electrons and protons are reviewed and it is shown that most of these observations can be explained by the interaction with flare plasma of a power law energy…

Astrophysics · Physics 2007-05-23 Vahe Petrosian
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