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Related papers: Onset of Electron Acceleration in a Flare Loop

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Based on the drift-kinetic theory, we develop a model for particle acceleration and transport in solar flares. The model describes the evolution of the particle distribution function by means of a numerical simulation of the drift-kinetic…

Solar and Stellar Astrophysics · Physics 2015-05-18 T. Minoshima , S. Masuda , Y. Miyoshi

Many particles are accelerated during solar flares. To understand the acceleration and propagation processes of electrons, we require the pitch-angle distributions of the particles. The pitch angle of accelerated electrons has been…

Solar and Stellar Astrophysics · Physics 2023-10-06 Keitarou Matsumoto , Satoshi Masuda , Takafumi Kaneko

We consider the acceleration of electrons in vacuum by means of the circularly-polirized electromagnetic wave, propagating along a magnetic field. We show that the electron energy growth, when using ultra-short and ultra-intense laser…

Accelerator Physics · Physics 2014-05-13 Robert Melikian

Electron acceleration to non-thermal energies is known to occur in low Mach number (M<5) shocks in galaxy clusters and solar flares, but the electron acceleration mechanism remains poorly understood. Using two-dimensional (2D)…

High Energy Astrophysical Phenomena · Physics 2014-11-26 Xinyi Guo , Lorenzo Sironi , Ramesh Narayan

The hard X-ray (HXR) emission in solar flares comes almost exclusively from a very small part of the flaring region, the footpoints of magnetic loops. Using RHESSI observations of solar flare footpoints, we determine the radial positions…

Solar and Stellar Astrophysics · Physics 2015-05-27 Marina Battaglia , Eduard P. Kontar

We investigate observational signatures of explosive chromospheric evaporation during a white-light flare (WLF) that occurred on 2022 August 27. Using the moment analysis, bisector techniques, and the Gaussian fitting method, red-shifted…

Solar and Stellar Astrophysics · Physics 2023-06-29 Dong Li , Chuan Li , Ye Qiu , Shihao Rao , Alexander Warmuth , Frederic Schuller , Haisheng Zhao , Fanpeng Shi , Jun Xu , Zongjun Ning

Electron acceleration mechanism at high Mach number collisionless shocks propagating in a weakly magnetized medium is investigated by a self-consistent two-dimensional particle-in-cell simulation. Simulation results show that strong…

Astrophysics · Physics 2008-12-18 Takanobu Amano , Masahiro Hoshino

We use 2D particle-in-cell (PIC) simulations to study the effect of the saturated whistler instability on the viscous heating and nonthermal acceleration of electrons in a shearing, collisionless plasma with a growing magnetic field,…

High Energy Astrophysical Phenomena · Physics 2017-12-06 Mario Riquelme , Alvaro Osorio , Eliot Quataert

In our recent paper (Solar Physics 261, 233) we investigated quasi-periodic oscillations of hard X-rays during impulsive phase of solar flares. We have come to conclusion that they are caused by magnetosonic oscillations of magnetic traps…

Solar and Stellar Astrophysics · Physics 2015-06-17 J. Jakimiec , M. Tomczak

We studied electron spectral indices of nonthermal emissions seen in hard X-rays (HXRs) and in microwaves. We analyzed 12 flares observed by the Hard X-ray Telescope aboard {\it Yohkoh}, Nobeyama Radio Polarimeters (NoRP), and the Nobeyama…

The angular distribution of electrons accelerated in solar flares is a key parameter in the understanding of the acceleration and propagation mechanisms that occur there. However, the anisotropy of energetic electrons is still a poorly…

Solar and Stellar Astrophysics · Physics 2012-12-24 Ewan Cameron Mackenzie Dickson , Eduard Kontar

In this paper, the energy budgets of two single-loop like flares observed in X- ray are analysed under the assumption that non-thermal electrons (NTEs) are the only source of plasma heating during all phases of both events. The flares were…

Solar and Stellar Astrophysics · Physics 2014-06-19 R. Falewicz

RHESSI measurements relevant to the fundamental processes of energy release and particle acceleration in flares are summarized. RHESSI's precise measurements of hard X-ray continuum spectra enable model-independent deconvolution to obtain…

Solar and Stellar Astrophysics · Physics 2011-10-11 R. P. Lin

We compare the characteristics of flare-accelerated energetic electrons at the Sun with those injected into interplanetary space. We have identified 17 energetic electron events well-observed with the SEPT instrument aboard STEREO which…

Solar and Stellar Astrophysics · Physics 2021-10-20 Nina Dresing , A. Warmuth , F. Effenberger , K. -L. Klein , S. Musset , L. Glesener , M. Brüdern

We model nanoflare heating of extrapolated active-region coronal loops via the acceleration of electrons and protons in Harris-type current sheets. The kinetic energy of the accelerated particles is estimated using semi-analytical and…

Solar and Stellar Astrophysics · Physics 2015-06-16 C. Gontikakis , S. Patsourakos , C. Efthymiopoulos , A. Anastasiadis , M. K. Georgoulis

We numerically explore electron acceleration and coronal heating by dissipative electric fields. Electrons are traced in linear force-free magnetic fields extrapolated from SOHO/MDI magnetograms, endowed with anomalous resistivity ($\eta$)…

Astrophysics · Physics 2009-11-11 Kaspar Arzner , Loukas Vlahos

Previous observations have not been able to exclude the possibility that high temperature active region loops are actually composed of many small scale threads that are in various stages of heating and cooling and only appear to be in…

Solar and Stellar Astrophysics · Physics 2014-11-20 Harry P. Warren , Amy R. Winebarger , David H. Brooks

The time evolution of the spectral index and the non-thermal flux in 24 impulsive solar hard X-ray flares of GOES class M was studied in RHESSI observations. The high spectral resolution allows for a clean separation of thermal and…

Astrophysics · Physics 2007-05-23 Paolo C. Grigis , Arnold O. Benz

The generation of nonthermal electrons during solar flares plays a critical role in energy transport from the corona to the chromosphere, producing regions of observed intense X-ray emission. Turbulence in post-flare loops, particularly…

Solar and Stellar Astrophysics · Physics 2026-02-05 Clarissa Mora , Fabio Bacchini , Rony Keppens

During solar flares, a large flux of energetic electrons propagate from the tops of reconnecting magnetic flux tubes toward the lower atmosphere. Over the course of the electrons' transport, a co-spatial counter-streaming return current is…

Solar and Stellar Astrophysics · Physics 2021-08-25 Meriem Alaoui , Gordon D. Holman , Joel C. Allred , Rafael T. Eufrasio