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Related papers: Soft X-ray microflares

200 papers

The nature of quasi-periodic pulsations in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent…

Solar and Stellar Astrophysics · Physics 2016-12-28 A. R. Inglis , J. Ireland , B. R. Dennis , L. A. Hayes , P. T. Gallagher

We present an analysis of soft X-ray (SXR) and extreme-ultraviolet (EUV) observations of solar flares with an approximate C8 GOES class. Our constraint on peak GOES SXR flux allows for the investigation of correlations between various flare…

Solar and Stellar Astrophysics · Physics 2013-05-09 Trevor A. Bowen , Paola Testa , Katharine K. Reeves

X-ray observations of solar flares routinely reveal an impulsive high-energy and a gradual low-energy emission component, whose relationship is one of the key issues of solar flare study. The gradual and impulsive emission components are…

Solar and Stellar Astrophysics · Physics 2015-05-20 Jingnan Guo , Siming Liu , Lyndsay Fletcher , Eduard P. Kontar

(Abridged) We report results from a comprehensive study of the nearby M dwarf Proxima Centauri with the XMM-Newton satellite. We find strongly variable coronal X-ray emission, with flares ranging over a factor of 100 in peak flux. The…

Astrophysics · Physics 2009-11-10 M. Guedel , M. Audard , F. Reale , S. L. Skinner , J. L. Linsky

Solar flares are one of the most energetic events in the solar system, their impact on Earth at ground level and its atmosphere remains under study. The repercussions of this phenomenon in our technological infrastructure includes radio…

Solar and Stellar Astrophysics · Physics 2018-08-29 V. De la Luz , E. P. Balanzario , T. Tsiftsi

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

On August 9, 2011, there was an X6.9 flare event occurred near the west limb of solar disk. From the observation obtained by the spectrometer of the Chinese Solar Broadband Radio Spectrometer in Huairou (SBRS/Huairou) around the flare, we…

Solar and Stellar Astrophysics · Physics 2015-03-13 Baolin Tan , Chengming Tan , Yuying Liu

Solar flares result from the rapid conversion of stored magnetic energy within the Sun's corona. These energy releases are associated with coronal magnetic loops, which are rooted in dense photospheric plasma and are passively transported…

Solar and Stellar Astrophysics · Physics 2025-03-28 M. Berretti , S. Mestici , L. Giovannelli , D. Del Moro , M. Stangalini , F. Giannattasio , F. Berrilli

A wide variety of solar system bodies are now known to radiate in the soft x-ray energy (<5 keV) regime. These include planets (Earth, Jupiter, Venus, Saturn, Mars): bodies having thick atmospheres, with or without intrinsic magnetic field;…

Astrophysics · Physics 2007-05-23 A. Bhardwaj

Power-law frequency distributions of the peak flux of solar flare X-ray emission have been studied extensively and attributed to a system of self-organized criticality (SOC). In this paper, we first show that, so long as the shape of the…

Solar and Stellar Astrophysics · Physics 2016-10-12 You-ping Li , Li Feng , Ping Zhang , Siming Liu , Weiqun Gan

We study a solar flare that occurred on September 10, 2002, in active region NOAA 10105 starting around 14:52 UT and lasting approximately 5 minutes in the radio range. The event was classified as M2.9 in X-rays and 1N in H\alpha. Solar…

Solar and Stellar Astrophysics · Physics 2015-06-11 C. G. Giménez de Castro , G. D. Cristiani , P. J. A. Simões , C. H. Mandrini , E. Correia , P. Kaufmann

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 demonstrate that for weak flares the dependence on spottedness can be rather weak. The fact is that such flares can occur both in small and large active regions. At the same time, powerful large flares of classes M and X occur much more…

Solar and Stellar Astrophysics · Physics 2022-09-07 M. M. Katsova , V. N. Obridko , D. D. Sokoloff , I. M. Livshits

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

This work reports a peculiar and interesting train of microwave type III pair bursts in the impulsive rising phase of a solar flare on 2011 September 26. The observations include radio spectrometers at frequency of 0.80 - 2.00 GHz, hard…

Solar and Stellar Astrophysics · Physics 2016-09-28 Baolin Tan , Marian Karlicky , Hana Meszarosova , Larisa Kashapova , Jing Huang , Yan Yan , Eduard P. Kontar

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

The properties of X-ray flashes (XRFs) and X-ray rich gamma-ray bursts (XRRs) as compared with classical gamma-ray bursts (C-GRBs) have been widely discussed during the \emph{Swift} era. It has been proposed that XRFs and XRRs are…

High Energy Astrophysical Phenomena · Physics 2025-05-13 Fan Xu , Yong-Feng Huang , Liang Li , Jin-Jun Geng , Xue-Feng Wu , Song-Bo Zhang , Chen Deng , Chen-Ran Hu , Xiao-Fei Dong , Hao-Xuan Gao

RHESSI observations of elementary flare bursts are presented. These solar flare elements are distinct emission peaks of a duration of some tens of seconds present in the hard X-ray light curves. They are characterized by consistent…

Astrophysics · Physics 2007-05-23 Paolo C. Grigis , Arnold O. Benz

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

In this work we study the correlation between the soft (1.6--12.4 keV, mostly thermal) and the hard (20--40 and 60--80 keV, mostly non-thermal) X-ray emission in solar flares up to the most energetic events, spanning about 4 orders of…

Astrophysics · Physics 2009-11-13 C. Isola , F. Favata , G. Micela , H. S. Hudson