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Related papers: Resolving Two Distinct Thermal X-ray Components in…

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We present a new analytical technique, combining Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) high-resolution imaging and spectroscopic observations, to visualize solar flare emission as a function of spectral component…

Instrumentation and Methods for Astrophysics · Physics 2015-09-15 Amir Caspi , Albert Y. Shih , James M. McTiernan , Säm Krucker

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

Solar hard X-ray observations provide diagnostics of the hottest plasmas and of nonthermal electron populations present during solar flares and coronal mass ejections. HXR images of specific energy ranges often contain overlapping…

Solar and Stellar Astrophysics · Physics 2026-01-14 Muriel Zoë Stiefel , Paolo Massa , Alessia Guidetti , Marina Battaglia , Säm Krucker

The extreme-ultraviolet (EUV) late phase of solar flares is a second peak of warm coronal emissions (e.g., Fe XVI) for many minutes to a few hours after the GOES soft X-ray peak. It was first observed by the EUV Variability Experiment (EVE)…

Solar and Stellar Astrophysics · Physics 2015-06-22 Y. Li , M. D. Ding , Y. Guo , Y. Dai

A number of double coronal X-ray sources have been observed during solar flares by RHESSI, where the two sources reside at different sides of the inferred reconnection site. However, where and how are these X-ray-emitting electrons…

Solar and Stellar Astrophysics · Physics 2022-07-20 Xiangliang Kong , Jing Ye , Bin Chen , Fan Guo , Chengcai Shen , Xiaocan Li , Sijie Yu , Yao Chen , Joe Giacalone

Solar flares and X-ray plasma ejections (XPEs) occur simultaneously but usually are separated spatially. We present two exceptional events observed by {\sl Yohkoh} in 2001 October 2 (event 1) and 2000 October 16 (event 2), in which features…

Solar and Stellar Astrophysics · Physics 2013-03-11 Michal Tomczak

In the classical flare picture, hard X-ray emission from the chromosphere is succeeded by soft-X-ray emission from hot plasma in the flare loop, the soft X-ray emission being a direct consequence of the impact of the non-thermal particle…

Solar and Stellar Astrophysics · Physics 2015-05-13 M. Battaglia , L. Fletcher , A. O. Benz

The chromospheric response to the input of flare energy is marked by extended extreme ultraviolet (EUV) ribbons and hard X-ray (HXR) footpoints. These are usually explained as the result of heating and bremsstrahlung emission from…

Solar and Stellar Astrophysics · Physics 2016-01-20 Paulo J. A. Simões , David R. Graham , Lyndsay Fletcher

We investigate the thermal properties of a solar flare by the observations of soft X-ray Telescope (XRT) on board Hinode and the Atmospheric Image Assembly on board the Solar Dynamics Observatory (SDO/AIA). Our analysis reveals a tenuous…

Solar and Stellar Astrophysics · Physics 2025-10-22 Xiaoyan Xie , Anna Chen , Crisel Suarez , Katharine K. Reeves , Soumya Roy , Christopher S. Moore , Nishu Karna , Joy Velasquez

Context: Solar flare hard X-rays (HXRs) are thought to be produced by nonthermal coronal electrons stopping in the chromosphere, or remaining trapped in the corona. The collisional thick target model (CTTM) predicts that sources produced by…

Solar and Stellar Astrophysics · Physics 2015-06-15 A. O'Flannagain , P. Gallagher , J. Brown , R. Milligan , G. Holman

In previous works we have developed a method to convert solar X-ray data, collected with the Yohkoh/SXT, into templates of stellar coronal observations. Here we apply the method to several solar flares, for comparison with stellar X-ray…

Astrophysics · Physics 2009-11-06 F. Reale , G. Peres , S. Orlando

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

The second peak in the Fe XVI 33.5 nm line irradiance observed during solar flares by Extreme ultraviolet Variability Experiment (EVE) is known as Extreme UltraViolet (EUV) late phase. Our previous paper (Liu et al. 2013) found that the…

Solar and Stellar Astrophysics · Physics 2015-04-22 Kai Liu , Yuming Wang , Jie Zhang , Xin Cheng , Rui Liu , Chenglong Shen

Plasmoids (or magnetic islands) are believed to play an important role in the onset of fast magnetic reconnection and particle acceleration during solar flares and eruptions. Direct imaging of flare current sheets and formation/ejection of…

Solar and Stellar Astrophysics · Physics 2025-01-22 Pankaj Kumar , Judith T. Karpen , Joel T. Dahlin

X-ray and EUV observations are an important diagnostic of various plasma parameters of the solar atmosphere during solar flares. Soft X-ray and EUV observations often show coronal sources near the top of flaring loops, while hard X-ray…

Solar and Stellar Astrophysics · Physics 2015-06-11 Marina Battaglia , Eduard P. Kontar

We analyze 19 bright variable X-ray sources detected in the XMM-Newton Extended Survey of the Taurus Molecular Cloud (XEST), in order to characterize the variations with time of their coronal properties and to derive informations on the…

With ASCA, we have detected three X-ray flares from the Class I protostar YLW15. The flares occurred every ~20 hours and showed an exponential decay with time constant 30-60 ks. The X-ray spectra are explained by a thin thermal plasma…

Astrophysics · Physics 2009-10-31 Yohko Tsuboi , Kensuke Imanishi , Katsuji Koyama , Nicolas Grosso , Thierry Montmerle

This paper reports on the re-analysis of solar flares in which the hard X-rays (HXRs) come predominantly from the corona rather than from the more usual chromospheric footpoints. All of the 26 previously analyzed event time intervals, over…

Solar and Stellar Astrophysics · Physics 2018-11-07 Brian R. Dennis , Miguel A. Duval-Poo , Michele Piana , Andrew R. Inglis , A. Gordon Emslie , Jingnan Guo , Yan Xu

The detection of very hot plasma in the quiescent corona is important for diagnosing heating mechanisms. The presence and the amount of such hot plasma is currently debated. The SphinX instrument on-board CORONAS-PHOTON mission is sensitive…

Solar and Stellar Astrophysics · Physics 2015-06-05 M. Miceli , F. Reale , S. Gburek , S. Terzo , M. Barbera , A. Collura , J. Sylwester , M. Kowalinski , P. Podgorski , M. Gryciuk

Solar flares are currently understood as the explosive release of energy stored in the form of stressed magnetic fields. In many cases, the released energy seems to take the form of large numbers of electrons accelerated to high energies or…

Solar and Stellar Astrophysics · Physics 2010-05-18 George H. Fisher