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Related papers: Onset of Electron Acceleration in a Flare Loop

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Finite thermal velocity modifications to electron slowing-down rates may be important for the deduction of solar flare total electron energy. Here we treat both slowing-down and velocity diffusion of electrons in the corona at flare…

Astrophysics · Physics 2009-11-11 Ross K. Galloway , Alexander L. MacKinnon , Eduard P. Kontar , Per Helander

Solar flares effectively accelerate particles to non-thermal energies. These accelerated electrons are responsible for energy transport and subsequent emissions in HXR, radio, and UV/EUV radiation. Due to the steeply decreasing electron…

Solar and Stellar Astrophysics · Physics 2026-01-01 Yingjie Luo , Eduard P. Kontar , Debesh Bhattacharjee

We study the evolution of the spectral index and the normalization (flux) of the non-thermal component of the electron spectra observed by RHESSI during 24 solar hard X-ray flares. The quantitative evolution is confronted with the…

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

The first self-consistent simulations of electron acceleration during magnetic reconnection in a macroscale system are presented. Consistent with solar flare observations the spectra of energetic electrons take the form of power-laws that…

In some flares the thermal component appears much earlier than the nonthermal component in X-ray range. Using sensitive microwave observations we revisit this finding made by Battaglia et al. (2009) based on RHESSI data analysis. We have…

Solar and Stellar Astrophysics · Physics 2015-06-11 Alexander A. Altyntsev , Gregory D. Fleishman , Sergey V. Lesovoi , Natalia S. Meshalkina

We consider particle acceleration to high energy via diffusive shock acceleration in a simple, self-consistent shock in jet model for blazars. Electrons are assumed to be accelerated at a shock front in relativistic jets and radiate…

Astrophysics · Physics 2007-05-23 F. M. Rieger , J. G. Kirk , A. Mastichiadis

We consider electron acceleration by obliquely propagating fast mode waves in magnetically dominated accretion disk coronae. For low coronal plasma densities, acceleration can exceed Coulomb drag at lower energies and energize electrons out…

Astrophysics · Physics 2016-08-30 Hui Li , James A. Miller

Context: Stochastic acceleration is thought to be a key mechanism in the energization of solar flare electrons. Aims: We study whether stochastic acceleration can reproduce the observed soft-hard-soft evolution of the spectral features of…

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

A popular scenario for electron acceleration in solar flares is transit-time damping of low-frequency MHD waves excited by reconnection and its outflows. The scenario requires several processes in sequence to yield energetic electrons of…

Astrophysics · Physics 2015-06-24 Arnold O. Benz , Pascal Saint-Hilaire

We investigate the type III radio bursts and X-ray signatures of accelerated electrons in a well observed solar flare in order to find the spatial properties of the acceleration region. Combining simultaneous RHESSI hard X-ray flare data…

Solar and Stellar Astrophysics · Physics 2015-05-27 H. A. S. Reid , N. Vilmer , E. P. Kontar

The aim of this paper is to investigate the spatial structure of the impulsive phase hard X-ray emission from solar flares. This work is motivated by the YOHKOH and the forthcoming HESSI observations. Summarizing past results, it is shown…

Astrophysics · Physics 2009-10-31 Vahe Petrosian , Timothy Q. Donaghy

The aim of the present paper is to use quasi-periodic oscillations in hard X-rays (HXRs) of solar flares as a diagnostic tool for investigation of impulsive electron acceleration. We have selected a number of flares which showed…

Solar and Stellar Astrophysics · Physics 2015-05-13 J. Jakimiec , M. Tomczak

Non-thermal particle acceleration in the solar corona is evident from both remote hard X-ray (HXR) sources in the chromosphere and direct in-situ detection in the heliosphere. Correlation of spectral indices between remote and in-situ…

Solar and Stellar Astrophysics · Physics 2025-02-27 Ross Pallister , Natasha L. S. Jeffrey , Morgan Stores

We analytically and numerically study the motion of electrons along a magnetic loop, to compare with the observation of the propagating feature of the non-thermal microwave source in the 1999 August 28 solar flare reported by Yokoyama et…

Astrophysics · Physics 2009-11-13 T. Minoshima , T. Yokoyama

We present a multi-wavelength observation of a solar flare occurring on 2006 December 13 with Hinode, RHESSI, and the Nobeyama Radio Observatory, to study the electron acceleration site and mechanism. The Solar Optical Telescope (SOT) on…

Solar and Stellar Astrophysics · Physics 2010-01-15 T. Minoshima , S. Imada , T. Morimoto , T. Kawate , H. Koshiishi , M. Kubo , S. Inoue , H. Isobe , S. Masuda , S. Krucker , T. Yokoyama

Impulsive solar energetic electrons are often observed in the interplanetary space near the Earth and have an attractive diagnostic potential for poorly understood solar flare acceleration processes. We investigate the transport of solar…

Solar and Stellar Astrophysics · Physics 2009-11-13 E. P. Kontar , H. A. S. Reid

We study the electron energy spectra of two powerful solar flares SOL2003-10-28T 11:06:16 (GOES class X17.2) and SOL2002-07-23T00:18:16 (X4.8) on the basis of HXR and gamma-ray spectra obtained from RHESSI data. Electron-electron (e-e)…

Solar and Stellar Astrophysics · Physics 2020-12-16 I. D. Oparin , Yu. E. Charikov , E. P. Ovchinnikova , A. N. Shabalin

Using {\em RHESSI} hard X-ray imaging spectroscopy observations, we analyze electron flux maps for a number of extended coronal loop flares. For each event, we fit a collisional model with an extended acceleration region to the observed…

Solar and Stellar Astrophysics · Physics 2015-06-05 Jingnan Guo , A. Gordon Emslie , Anna Maria Massone , Michele Piana

Solar flares are explosive releases of magnetic energy stored in the solar corona, driven by magnetic reconnection. These events accelerate electrons, generating hard X-ray emissions and often display Quasi Periodic Pulsations (QPPs) across…

Solar and Stellar Astrophysics · Physics 2025-11-25 Luiz A. C. A. Schiavo , Natasha L. S. Jeffrey , Gert J. J. Botha , James A. McLaughlin

X-ray observations provide important and valuable insights into the acceleration and propagation of nonthermal electrons during solar flares. Improved X-ray spectral analysis requires a deeper understanding of the dynamics of energetic…

Solar and Stellar Astrophysics · Physics 2024-10-15 Yingjie Luo , Eduard P. Kontar , Debesh Bhattacharjee