English
Related papers

Related papers: Evolution of Flare-accelerated Electrons Quantifie…

200 papers

Aims: This work aims to identify the mechanism driving pulsations in hard X-ray (HXR) and microwave emission during solar flares. Here, by using combined HXR and microwave observations from Solar Orbiter/STIX and EOVSA we investigate an…

Solar and Stellar Astrophysics · Physics 2024-05-01 Hannah Collier , Laura A. Hayes , Sijie Yu , Andrea F. Battaglia , William Ashfield , Vanessa Polito , Louise K. Harra , Säm Krucker

With the elementary energy release events introduced in a previous paper (Liu & Fletcher 2009) we model the chromospheric evaporation in flaring loops. The thick-target hard X-ray (HXR) emission produced by electrons escaping from the…

Solar and Stellar Astrophysics · Physics 2014-11-20 Siming Liu , Feiran Han , Lyndsay Fletcher

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

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

The aim of this study is to generate maps of the hard X-ray emission produced by energetic electrons in a solar flare and compare them with observations. The ultimate goal is to test the viability of the combined MHD/test-particle approach…

Solar and Stellar Astrophysics · Physics 2020-11-04 Mykola Gordovskyy , Philippa K. Browning , Satoshi Inoue , Eduard P. Kontar , Kanya Kusano , Grigory E. Vekstein

The interrelation of hard X-ray (HXR) emitting sources and the underlying physics of electron acceleration and transport presents one of the major questions in high-energy solar flare physics. Spatially resolved observations of solar flares…

Solar and Stellar Astrophysics · Physics 2015-06-12 Paulo J. A. Simões , Eduard P. Kontar

Recently, a number of peculiar flares have been reported, which demonstrate significant non-thermal particle signatures with a low, if any, thermal emission, that implies close association of the observed emission with the primary energy…

Solar flare hard X-rays (HXRs) are produced as bremsstrahlung when an accelerated population of electrons interacts with the dense chromospheric plasma. HXR observations presented by using the Ramaty High-Energy Solar Spectroscopic Imager…

Solar and Stellar Astrophysics · Physics 2014-11-20 A. O'Flannagain , J. C. Brown , P. T. Gallagher

We identify a set of ~100 "cold" solar flares and perform a statistical analysis of them in the microwave range. Cold flares are characterized by a weak thermal response relative to nonthermal emission. This work is a follow up of a…

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…

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

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

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

The excess broadening of high-temperature spectral lines, long observed near the tops of flare arcades, is widely considered to result from magnetohydrodynamic (MHD) turbulence. According to different theories, plasma turbulence is also…

Solar and Stellar Astrophysics · Physics 2024-07-18 William Ashfield , Vanessa Polito , Sijie Yu , Hannah Collier , Laura Hayes

In order to study the acceleration and propagation of bremsstrahlung-producing electrons in solar flares, we analyze the evolution of the flare loop size with respect to energy at a variety of times. A GOES M3.7 loop-structured flare…

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

X-rays are a valuable diagnostic tool for the study of high energy accelerated electrons. Bremsstrahlung X-rays produced by, and directly related to, high energy electrons accelerated during a flare, provide a powerful diagnostic tool for…

Solar and Stellar Astrophysics · Physics 2015-03-09 Natasha L. S. Jeffrey

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…

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

We study the release of energy during the gradual phase of a flare, characterized by faint bursts of non-thermal hard X-ray (HXR) emission associated with decimetric radio spikes and type III radio bursts starting at high frequencies and…

Solar and Stellar Astrophysics · Physics 2021-01-20 Sophie Musset , Eduard Kontar , Lindsay Glesener , Nicole Vilmer , Abdallah Hamini

The impulsive phase of a solar flare is known to generate strong turbulence and to transfer magnetic energy into accelerated electrons. Recognizing the importance of angular diffusion on the dynamics of the accelerated electrons, we extend…

Solar and Stellar Astrophysics · Physics 2026-03-30 A. Gordon Emslie , Eduard P. Kontar