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Related papers: Flare Impulsive-phase Durations

200 papers

RHESSI observations are used to quantitatively study the hard X-ray evolution in 5 large solar flares selected for spectral hardening in the course of the event. The X-ray bremsstrahlung emission from non-thermal electrons is characterized…

Astrophysics · Physics 2008-11-07 Paolo C. Grigis , Arnold O. Benz

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

The study of the localized plasma conditions before the impulsive phase of a solar flare can help us understand the physical processes that occur leading up to the main flare energy release. Here, we present evidence of a hot X-ray onset…

Solar and Stellar Astrophysics · Physics 2020-12-02 Hugh S. Hudson , Paulo J. A. Simoes , Lyndsay Fletcher , Laura A. Hayes , Iain G. Hannah

We present the first systematic investigation of the morphological and timing properties of flares in GRBs observed by Swift/XRT. We consider a large sample drawn from all GRBs detected by Swift, INTEGRAL and HETE-2 prior to 2006 Jan 31,…

We present high spatial resolution observations of chromospheric evaporation in the flare SOL2014-03-29T17:48. Interface Region Imaging Spectrograph (IRIS) observations of the FeXXI 1354.1 A line indicate evaporating plasma at a temperature…

Solar and Stellar Astrophysics · Physics 2015-11-11 Marina Battaglia , Lucia Kleint , Säm Krucker , David Graham

We present a multiwavelength analysis of the long duration flare observed on 15 April 2002 (soft X-ray peak time at 03:55 UT, SOL2002-04-15T03:55). This flare occurred on the disk (S15W01) in NOAA 9906 and was observed by a number of space…

Solar and Stellar Astrophysics · Physics 2020-03-11 A. Kepa , B. Sylwester , J. Sylwester , T. Mrozek , M. Siarkowski

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

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

In this study, we investigate motions in the hot plasma above the flare loops during the 2017 September 10 X8.2 flare event. We examine the region to the south of the main flare arcade, where there is data from the Interface Region Imaging…

Solar and Stellar Astrophysics · Physics 2021-01-06 Katharine K. Reeves , Vanessa Polito , Bin Chen , Giselle Galan , Sijie Yu , Wei Liu , Gang Li

Twisted magnetic fields should be ubiquitous in flare-producing active regions where the magnetic fields are strongly non-potential. It has been shown that reconnection in helical magnetic coronal loops results in plasma heating and…

Solar and Stellar Astrophysics · Physics 2016-01-20 R. F. Pinto , M. Gordovskyy , P. K. Browning , N. Vilmer

Plasma turbulence is thought to be associated with various physical processes involved in solar flares, including magnetic reconnection, particle acceleration and transport. Using Ramaty High Energy Solar Spectroscopic Imager ({\it RHESSI})…

Solar and Stellar Astrophysics · Physics 2015-05-27 E. P. Kontar , I. G. Hannah , N. H. Bian

We studied long duration flare observed with Nobeyama Radioheliograph at frequencies 17 and 34 GHz and with Ramaty High Energy Solar Spectroscopic Imager at 25-50 keV. We found that microwave and hard X-ray emission variation contain…

Solar and Stellar Astrophysics · Physics 2011-10-07 Veronika Reznikova , Kiyoto Shibasaki

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 present radio and X-ray observations of an impulsive solar flare that was moderately intense in microwaves, yet showed very meager EUV and X-ray emission. The flare occurred on 2001 Oct 24 and was well-observed at radio wavelengths by…

Astrophysics · Physics 2009-06-23 T. S. Bastian , G. D. Fleishman , D. E. Gary

We present the analyses of intense X-ray flares detected on the active fast rotator AB Dor using observations from the XMM-Newton. A total of 21 flares are detected, and 13 flares are analysed in detail. The total X-ray energy of these…

Solar and Stellar Astrophysics · Physics 2023-10-23 Shweta Didel , Jeewan C. Pandey , A. K. Srivastava , Gurpreet Singh

We analyze high cadence high resolution observations of a C3.2 flare obtained by AIA/SDO on August 1, 2010. The flare is a long duration event with soft X-ray and EUV radiation lasting for over four hours. Analysis suggests that magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-03 Jiong Qiu , Wen-Juan Liu , Dana W. Longcope

We use more than 4,500 microflares from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) microflare data set (Christe et al., 2008, Ap. J., 677, 1385) to estimate electron densities and volumetric filling factors of…

Solar and Stellar Astrophysics · Physics 2011-07-21 R. N. Baylor , P. A. Cassak , S. Christe , I. G. Hannah , Säm Krucker , D. J. Mullan , M. A. Shay , H. S. Hudson , R. P. Lin

Based on a sample of 1114 flares observed simultaneously in hard X-rays (HXR) by the BATSE instrument and in soft X-rays (SXR) by GOES, we studied several aspects of the Neupert effect and its interpretation in the frame of the…

Astrophysics · Physics 2009-11-07 A. Veronig , B. Vrsnak , B. R. Dennis , M. Temmer , A. Hanslmeier , J. Magdalenic

The thick-target model predicts that in flare foot points, we should observe lowering of HXR sources' altitude with increasing energy. The foot point of HXR sources result from the direct interaction of non-thermal electron beams with…

Solar and Stellar Astrophysics · Physics 2022-03-14 T. Mrozek , R. Falewicz , S. Kolomanski , M. Litwicka

Temporal and spectral characteristics of X-ray emission from 60 flares of intensity $\ge$C class observed by Solar X-ray Spectrometer (SOXS) during 2003-2011 are presented. We analyse the X-ray emission observed in four and three energy…

Solar and Stellar Astrophysics · Physics 2018-10-17 Veena Choithani , Rajmal Jain , Arun Kumar Awasthi , Geetanjali Singh , Sneha Chaudhari , Som Kumar Sharma