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Related papers: Thermal and non-thermal energies in solar flares

200 papers

Solar flares show remarkable variety of the energy partitioning between thermal and nonthermal components. Those with a prominent nonthermal component but only a modest thermal one are particularly well suited to study the direct effect of…

Solar and Stellar Astrophysics · Physics 2020-02-26 Galina G. Motorina , Gregory D. Fleishman , Eduard P. Kontar

In solar flares, energy is released impulsively and is partly converted into thermal energy of hot plasmas and kinetic energy of accelerated nonthermal particles. Despite numerous efforts, no consensus on quantifying this energy balance has…

Solar and Stellar Astrophysics · Physics 2021-01-04 Alexander Warmuth , Gottfried Mann

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

Extending previous studies of nonthermal electron transport in solar flares which include the effects of collisional energy diffusion and thermalization of fast electrons, we present an analytic method to infer more accurate estimates of…

Solar and Stellar Astrophysics · Physics 2015-08-19 E. P. Kontar , N. L. S. Jeffrey , A. G. Emslie , N. H. Bian

Non-potential magnetic energy promptly released in solar flares is converted to other forms of energy. This may include nonthermal energy of flare-accelerated particles, thermal energy of heated flaring plasma, and kinetic energy of…

Solar and Stellar Astrophysics · Physics 2021-06-09 Gregory D. Fleishman , Lucia Kleint , Galina G. Motorina , Gelu M. Nita , Eduard P. Kontar

We investigate the influence of the variations of energy spectrum of non-thermal electrons on the resulting GOES classes of solar flares. Twelve observed flares with various soft to hard X-ray emission ratios were modelled using different…

Solar and Stellar Astrophysics · Physics 2009-09-25 R. Falewicz , P. Rudawy , M. Siarkowski

Non-thermal and thermal parameters of 85 solar flares of GOES class B1 to M6 (background subtracted classes A1 to M6) have been compared to each other. The hard X-ray flux has been measured by RHESSI and a spectral fitting provided flux and…

Astrophysics · Physics 2009-11-11 Marina Battaglia , Paolo C. Grigis , Arnold O. Benz

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

This paper presents measurements of the energy radiated by the lower solar atmosphere, at optical, UV, and EUV wavelengths, during an X-class solar flare (SOL2011-02-15T01:56) in response to an injection of energy assumed to be in the form…

A new estimation of the total number and energy of the non-thermal electrons produced in the giant ($>\text{X}17$) solar flare on 2003 October 28 is presented based on the analysis of the observations of the hard X-ray (HXR) emission by the…

Solar and Stellar Astrophysics · Physics 2018-09-05 B. A. Nizamov , I. V. Zimovets , D. V. Golovin , A. B. Sanin , M. L. Litvak , V. I. Tretyakov , I. G. Mitrofanov , A. S. Kozyrev

The energy released in a solar flare is partitioned between thermal and non-thermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the…

Astrophysics · Physics 2011-02-11 J. C. Raymond , G. Holman , A. Ciaravella , A. Panasyuk , Y. -K. Ko , J. Kohl

This study entails the third part of a global flare energetics project, in which Ramaty High-Energy Solar Spectroscopic Imager (RHESSI) data of 191 M and X-class flare events from the first 3.5 yrs of the Solar Dynamics Observatory (SDO)…

Solar and Stellar Astrophysics · Physics 2018-03-28 Markus J. Aschwanden , Gordon Holman , Aidan O'Flannagain , Amir Caspi , James M. McTiernan , Eduard Kontar

One of the key problems in solar flare physics is the determination of the low-energy cut-off; the value that determines the energy of nonthermal electrons and hence flare energetics. We discuss different approaches to determine the…

Solar and Stellar Astrophysics · Physics 2019-08-14 Markus Aschwanden , Eduard P. Kontar , Natasha L. S. Jeffrey

During solar flares, a large fraction of the released magnetic energy is carried by energetic electrons that transfer and deposit energy in the Sun's atmosphere. Electron transport is often approximated by a cold thick-target model (CTTM),…

Solar and Stellar Astrophysics · Physics 2019-08-09 Natasha L. S. Jeffrey , Eduard P. Kontar , Lyndsay Fletcher

The disparate nature of thermal-nonthermal energy partition during flares, particularly during weak flares, is still an open issue. Following the Neupert effect, quantifying the relative yield of X-ray emission in different energy bands can…

Solar and Stellar Astrophysics · Physics 2024-02-06 Arun Kumar Awasthi , Tomasz Mrozek , Sylwester Kołomański , Michalina Litwicka , Marek Stęślicki , Karol Kułaga

A primary characteristic of solar flares is the efficient acceleration of electrons to nonthermal deka-keV energies. While hard X-Ray (HXR) observation of bremsstrahlung emission serves as the key diagnostic of these electrons. In this…

Solar and Stellar Astrophysics · Physics 2025-06-11 Debesh Bhattacharjee , Eduard P. Kontar , Yingjie Luo

Solar flare X-ray spectra are typically dominated by thermal bremsstrahlung emission in the soft X-ray ($\lesssim$10 keV) energy range; for hard X-ray energies ($\gtrsim$30 keV), emission is typically non-thermal from beams of electrons.…

Solar and Stellar Astrophysics · Physics 2020-04-08 James M. McTiernan , Amir Caspi , Harry P. Warren

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

Investigate particle acceleration and heating in a solar microflare. In a microflare with non-thermal emission to remarkably high energies ($>50$ keV), we investigate the hard X-rays with RHESSI imaging and spectroscopy and the resulting…

Astrophysics · Physics 2010-09-17 I. G. Hannah , S. Krucker , H. S. Hudson , S. Christe , R. P. Lin

We study the non-thermal emissions in a solar flare occurring on 2003 May 29 by using RHESSI hard X-ray (HXR) and Nobeyama microwave observations. This flare shows several typical behaviors of the HXR and microwave emissions: time delay of…

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