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Related papers: Solar flare electron acceleration: comparing theor…

200 papers

We develop a model for stochastic acceleration of electrons in solar flares. As in several previous models, the electrons are accelerated by turbulent fast magnetosonic waves ("fast waves") via transit-time-damping (TTD) interactions. (In…

Solar and Stellar Astrophysics · Physics 2015-06-19 Peera Pongkitiwanichakul , Benjamin D. G. Chandran

Solar flare electron acceleration is an extremely efficient process, but the method of acceleration is not well constrained. Two of the essential diagnostics: electron anisotropy (velocity angle to the guiding magnetic field) and the high…

Solar and Stellar Astrophysics · Physics 2020-12-21 Natasha L. S. Jeffrey , Pascal Saint-Hilaire , Eduard P. Kontar

During solar flares a large amount of electrons with energies greater than 20 keV is generated with a production rate of typically $10^{36}$ s$^{-1}$. A part of them is able to propagate along open magnetic field lines through the corona…

Solar and Stellar Astrophysics · Physics 2015-11-11 F. Breitling , G. Mann , C. Vocks

Context. We introduce a model for including accelerated particles in pure magnetohydrodynamics (MHD) simulations of the solar atmosphere. Aims. We show that the method is viable and produces results that enhance the realism of MHD…

Solar and Stellar Astrophysics · Physics 2018-12-05 Helle Bakke , Lars Frogner , Boris Vilhelm Gudiksen

We investigate the signature of the photospheric albedo contribution in solar flare hard X-ray spectra, the effect of low energy cutoffs in electron spectra, and the directivity of hard X-ray emission. Using Ramaty High Energy Solar…

Astrophysics · Physics 2008-11-26 J. Kasparova , E. P. Kontar , J. C. Brown

A multi-wavelength spatial and temporal analysis of solar high energy electrons is conducted using the August 20, 2002 flare of an unusually flat (gamma=1.8) hard X-ray spectrum. The flare is studied using RHESSI, Halpha, radio, TRACE, and…

Astrophysics · Physics 2008-11-26 J. Kasparova , M. Karlicky , E. P. Kontar , R. A. Schwartz , B. R. Dennis

Red-shifted components of chromospheric emission lines in the hard X-ray impulsive phase of solar flares have recently been studied through their 30 s evolution with the high resolution of IRIS. Radiative-hydrodynamic flare models show that…

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

We study spectroscopic observations of chromospheric evaporation mass flows in comparison to the energy input by electron beams derived from hard X-ray data for the white-light M2.5 flare of 2006 July 6. The event was captured in high…

Solar and Stellar Astrophysics · Physics 2015-05-19 A. M. Veronig , J. Rybak , P. Gömöry , S. Berkebile-Stoiser , M. Temmer , W. Otruba , B. Vrsnak , W. Pötzi , D. Baumgartner

Aims. The H-alpha emission of solar flare kernels and associated hard X-ray (HXR) emission often show similar time variations but their light curves are shifted in time by energy transfer mechanisms. We searched for fast radiative response…

Solar and Stellar Astrophysics · Physics 2015-05-30 K. Radziszewski , P. Rudawy , K. J. H. Phillips

The radio emission during 201 X-ray selected solar flares was surveyed from 100 MHz to 4 GHz with the Phoenix-2 spectrometer of ETH Zurich. The selection includes all RHESSI flares larger than C5.0 jointly observed from launch until June…

Astrophysics · Physics 2009-11-10 Arnold O. Benz , Paolo Grigis , Andre Csillagy , Pascal Saint-Hilaire

High-energy solar flares have shown to have at least two distinct phases: prompt-impulsive and delayed-gradual. Identifying the mechanism responsible for accelerating the electrons and ions and the site at which it occurs during these two…

Solar and Stellar Astrophysics · Physics 2021-09-29 Melissa Pesce-Rollins , Nicola Omodei , Vahe' Petrosian , Francesco Longo

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

Polarization measurements of hard X-rays from solar flares can provide a direct handle on the extent to which the accelerated electrons are beamed, which, in turn, has important implications for particle acceleration models. Past efforts to…

Astrophysics · Physics 2009-11-07 M. L. McConnell , J. M. Ryan , D. M. Smith , R. P. Lin , A. G. Emslie

This article broadly reviews our knowledge of solar flares. There is a particular focus on their global properties, as opposed to the microphysics such as that needed for magnetic reconnection or particle acceleration as such. Indeed solar…

Solar and Stellar Astrophysics · Physics 2011-08-18 Hugh S. Hudson

Microflares are energetically smaller versions of solar flares, demonstrating the same processes of plasma heating and particle acceleration. However, it remains unclear down to what energy scales this impulsive energy release continues,…

Solar and Stellar Astrophysics · Physics 2024-02-09 Kristopher Cooper , Iain G. Hannah , Lindsay Glesener , Brian W. Grefenstette

Kontar et al. (2004) have shown how to recover mean source electron spectra in solar flares through a physical constraint regularization analysis of the bremsstrahlung photon spectra that they produce. They emphasize the use of non-square…

Astrophysics · Physics 2009-11-10 E. P. Kontar , A. G. Emslie , M. Piana , A. M. Massone , J. C. Brown

Observations of radio noise storms can act as sensitive probes of nonthermal electrons produced in small acceleration events in the solar corona. We use data from noise storm episodes observed jointly by the Giant Metrewave Radio Telescope…

Solar and Stellar Astrophysics · Physics 2018-05-22 Tomin James , Prasad Subramanian

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 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
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