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Related papers: Impulsive Thermal X-ray Emission from a Low-lying …

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It is well known among the scientific community that solar flare activity often begins well before the main impulsive energy release. Our aim is to investigate the earliest phase of four distinct flares observed by Solar Orbiter/STIX and…

Coronal hard X-ray (HXR) and continuum gamma-ray sources associated with the impulsive phase of solar flares have been the subject of renewed interest in recent years. They have been interpreted in terms of thin-target, nonthermal…

Solar and Stellar Astrophysics · Physics 2015-05-30 Bin Chen , Timothy S. Bastian

We report high-resolution observations at mid-infrared wavelengths of a minor solar flare, SOL2014-09-24T17T17:50 (C7.0), using Quantum Well Infrared Photodetector (QWIP) cameras at an auxiliary of the McMath-Pierce telescope. The flare…

Solar and Stellar Astrophysics · Physics 2016-03-23 M Penn , S Krucker , H Hudson , M Jhabvala , D Jennings , A Lunsford , P Kaufmann

The Sun offers a convenient nearby laboratory to study the physical processes of particle acceleration and impulsive energy release in magnetized plasmas that occur throughout the universe, from planetary magnetospheres to black hole…

Solar and Stellar Astrophysics · Physics 2011-05-13 Amir Caspi

This paper investigates the temporal evolution of temperature, emission measure, energy loss and velocity in a C-class solar flare from both an observational and theoretical perspective. The properties of the flare were derived by following…

Astrophysics · Physics 2009-11-13 Claire L. Raftery , Peter T. Gallagher , Ryan O. Milligan , James A. Klimchuk

A large arcade flare of 2 March 1993 has been investigated using X-ray observations recorded by the {\sl Yohkoh} and GOES satellites and the {\sl Compton Gamma Ray Observatory}. We analyzed quasi-periodicity of the hard-X-ray (HXR) pulses…

Solar and Stellar Astrophysics · Physics 2015-06-18 Jerzy Jakimiec , Michal Tomczak

Recent observations in extreme-ultraviolet (EUV) wavelengths reveal a new late phase in some solar flares, which is seen as a second peak in warm coronal emissions ($\sim3$ MK) several tens of minutes to a few hours after the soft X-ray…

Solar and Stellar Astrophysics · Physics 2021-08-04 Y. Zhong , Y. Dai , M. D. Ding

Explosive transient events occur throughout the solar atmosphere. The differing manifestations range from coronal mass ejections to Ellerman bombs. The former may have negligible signatures in the lower atmosphere, and the latter may have…

Solar and Stellar Astrophysics · Physics 2024-08-06 L. P. Chitta , I. G. Hannah , L. Fletcher , H. S. Hudson , P. R. Young , S. Krucker , H. Peter

We report hard X-ray and gamma-ray observations of the impulsive phase of the SOL2017-09-06T11:55 X9.3 solar flare. We focus on a high-energy part of the spectrum, >100 keV, and perform time resolved spectral analysis for a portion of the…

High Energy Astrophysical Phenomena · Physics 2019-06-11 Alexandra L. Lysenko , Sergey A. Anfinogentov , Dmitry D. Svinkin , Dmitry D. Frederiks , Gregory D. Fleishman

Observations of a rare long-duration solar event of GOES class X1.2 from 26 October 2003 are presented. This event showed a pronounced burst of hard X-ray and microwave emission, which was extremely delayed (>60 min) with respect to the…

Solar and Stellar Astrophysics · Physics 2015-06-05 I. V. Zimovets , A. B. Struminsky

The new generations of multiwavelength radioheliographs with high spatial resolution will employ microwave imaging spectropolarimetry to recover flare topology and plasma parameters in the flare sources and along the wave propagation paths.…

Solar and Stellar Astrophysics · Physics 2017-09-27 A. Altyntsev , N. Meshalkina , I. Myshyakov , V. Pal`shin , G. Fleishman

It is recently noted that solar eruptions can be associated with the contraction of coronal loops that are not involved in magnetic reconnection processes. In this paper, we investigate five coronal eruptions originating from four sigmoidal…

Solar and Stellar Astrophysics · Physics 2015-06-11 Rui Liu , Chang Liu , Tibor Török , Yuming Wang , Haimin Wang

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

Flare loops form an integral part of eruptive events, being detected in the range of temperatures from X-rays down to cool chromospheric-like plasmas. While the hot loops are routinely observed by the Solar Dynamics Observatory's…

Solar and Stellar Astrophysics · Physics 2020-01-08 Július Koza , David Kuridze , Petr Heinzel , Sonja Jejčič , Huw Morgan , Maciej Zapiór

One of the key processes associated with the "standard" flare model is chromospheric evaporation, a process where plasma heated to high temperatures by energy deposition at the flare footpoints is driven upwards into the corona. Despite…

Strong solar flares and coronal mass ejections, here defined not only as the bursts of electromagnetic radiation but as the entire process in which magnetic energy is released through magnetic reconnection and plasma instability, emanate…

Solar and Stellar Astrophysics · Physics 2019-05-29 Shin Toriumi , Haimin Wang

Where particle acceleration and plasma heating take place in relation to magnetic reconnection is a fundamental question for solar flares. We report analysis of an M7.7 flare on 2012 July 19 observed by SDO/AIA and RHESSI. Bi-directional…

Solar and Stellar Astrophysics · Physics 2014-04-04 Wei Liu , Qingrong Chen , Vahe' Petrosian

We investigate accelerated electron energy spectra for different sources in a large flare using simultaneous observations obtained with two instruments, the Nobeyama Radio Heliograph (NoRH) at 17 and 34 GHz, and the Reuven Ramaty High…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. R. Kundu , V. V. Grechnev , S. M. White , E. J. Schmahl , N. S. Meshalkina , L. K. Kashapova

Using RHESSI and some auxiliary observations we examine possible connections between spatial and temporal morphology of the sources of non-thermal hard X-ray (HXR) emission which revealed minute quasi-periodic pulsations (QPPs) during the…

Astrophysics · Physics 2015-05-13 I. V. Zimovets , A. B. Struminsky

Efficient radiation at second and/or higher harmonics of Wce has been suggested to circumvent the escaping difficulty of the electron cyclotron maser emission mechanism when it is applied to solar radio bursts, such as spikes. In our…

Solar and Stellar Astrophysics · Physics 2022-09-15 Mehdi Yousefzadeh , Yao Chen , Hao Ning , Mahboub Hosseinpour