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Related papers: Solar flares as electron accelerators: toward a re…

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During a solar flare, electrons are accelerated to non-thermal energies as a result of magnetic reconnection. These electrons then propagate upwards and downwards from the energy release site along magnetic field lines and produce radio and…

Solar and Stellar Astrophysics · Physics 2025-03-04 Shilpi Bhunia , Laura A. Hayes , Karl Ludwig Klein , Nicole Vilmer , Shane A. Maloney , Peter T. Gallagher

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

Context: The strong electric fields associated with magnetic reconnection in solar flares are a plausible mechanism to accelerate populations of high energy, non-thermal particles. One such reconnection scenario occurs at a 3D magnetic null…

Solar and Stellar Astrophysics · Physics 2015-06-03 Adam J. Stanier , Philippa K. Browning , Silvia Dalla

Even small solar flares can display a surprising level of complexity regarding their morphology and temporal evolution. Many of their properties, such as energy release and electron acceleration can be studied using highly complementary…

Solar and Stellar Astrophysics · Physics 2021-12-08 Marina Battaglia , Rohit Sharma , Yingjie Luo , Bin Chen , Sijie Yu , Säm Krucker

Solar photospheric convection drives myriads of dissipative Alfven solitons (hereinafter called alfvenons) capable of accelerating electrons and ions to energies of hundreds of keV and producing the X-ray corona. Alfvenons are exact…

Astrophysics · Physics 2009-09-29 K. Stasiewicz

X-radiation from energetic electrons is the prime diagnostic of flare-accelerated electrons. The observed X-ray flux (and polarization state) is fundamentally a convolution of the cross-section for the hard X-ray emission process(es) in…

Generally, large solar flares accelerate electrons to high energies more efficiently than microflares. However, some microflares, known as hard microflares (HMFs), also produce high-energy electrons, as indicated by their flat hard X-ray…

The mechanism that accelerates particles to the energies required to produce the observed high-energy impulsive emission in solar flares is not well understood. Drake et al. (2006) proposed a mechanism for accelerating electrons in…

Solar and Stellar Astrophysics · Physics 2016-03-23 S. E. Guidoni , C. R. DeVore , J. T. Karpen , B. J. Lynch

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

There are still debates whether particle acceleration in solar flares may occur due to interruption of electric currents flowing along magnetic loops. To contribute to this problem, we performed the first statistical study of relationships…

Solar and Stellar Astrophysics · Physics 2020-03-25 I. V. Zimovets , I. N. Sharykin , W. Q. Gan

The aim of the thesis is the study of properties of solar flares via reconstruction of energy distributions of accelerated/heated electrons, diagnostics of flare plasma based on EUV and X-ray observations, as well as the estimation of the…

Solar and Stellar Astrophysics · Physics 2017-10-31 Galina G. Motorina

We present an up-to-date review of the physics of electron acceleration in solar noi se storms. We describe the observed characteristics of noise storm emission, emphasi zing recent advances in imaging observations. We briefly describe the…

Astrophysics · Physics 2007-05-23 Prasad Subramanian

We review basic theoretical concepts in particle acceleration, with particular emphasis on processes likely to occur in regions of magnetic reconnection. Several new developments are discussed, including detailed studies of reconnection in…

The 'standard solar' flare model collects all physical ingredients identified by multi-wavelength observations of our Sun: magnetic reconnection, fast particle acceleration and the resulting emission at various wavelengths, especially in…

Solar and Stellar Astrophysics · Physics 2020-06-24 Wenzhi Ruan , Chun Xia , Rony Keppens

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

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 are powerful particle accelerators, and in the accepted standard flare model most of the flare energy is transported from a coronal energy-release region by accelerated electrons which stop collisionally in the chromosphere,…

Solar and Stellar Astrophysics · Physics 2024-06-18 Paulo J. A. Simões , Lyndsay Fletcher , Hugh S. Hudson , Graham S. Kerr , Matt Penn , Karla F. Lopez

The X8.2-class limb flare on September 10, 2017 is among the best studied solar flare events owing to its great similarity to the standard flare model and the broad coverage by multiple spacecraft and ground-based observations. These…

Solar and Stellar Astrophysics · Physics 2022-06-29 Xiaocan Li , Fan Guo , Bin Chen , Chengcai Shen , Lindsay Glesener

The standard flare model, despite its success, is limited in comprehensively explaining the various processes involving nonthermal particles. One such missing ingredient is a detailed understanding of the various processes involved during…

Solar and Stellar Astrophysics · Physics 2024-04-23 Surajit Mondal , Andrea F. Battaglia , Bin Chen , Sijie Yu