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Related papers: A Hot Microflare Observed With RHESSI and Hinode

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The million degree plasma of the solar corona must be supplied by the underlying layers of the atmosphere. The mechanism and location of energy release, and the precise source of coronal plasma, remain unresolved. In earlier work we pursued…

Solar and Stellar Astrophysics · Physics 2016-03-23 Stephen J. Bradshaw , James A. Klimchuk

We investigate two microflares of GOES classes A9 and C1 (after background subtraction) observed by STIX onboard Solar Orbiter with exceptionally strong nonthermal emission. We complement the hard X-ray imaging and spectral analysis by STIX…

Solar and Stellar Astrophysics · Physics 2024-03-12 Jonas Saqri , Astrid M. Veronig , Andrea Francesco Battaglia , Ewan C. M. Dickson , Dale E. Gary , Säm Krucker

Soft X-ray spectra 3.33 A - 6.15 A from the RESIK instrument on CORONAS-F constitute a unique database for the study of the physical conditions of solar flare plasmas, enabling the calculation of differential emission measures. The two…

Solar and Stellar Astrophysics · Physics 2020-10-14 A. Kepa , R. Falewicz , M. Siarkowski , M. Pietras

Microflares, one of small-scale solar activities, are believed to be caused by magnetic reconnection. Nevertheless, their three-dimensional (3D) magnetic structures, thermodynamic structures, and physical links to the reconnection have been…

Solar and Stellar Astrophysics · Physics 2022-05-18 Z. F. Li , X. Cheng , F. Chen , J. Chen , M. D. Ding

The Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft observed flare footpoint regions coincident with a surge for a M3.7 flare observed on 25 September 2011 at N12 E33 in active region 11302. The flare was observed in…

Solar and Stellar Astrophysics · Physics 2015-10-30 George A. Doschek , Harry P. Warren , Brian R. Dennis , Jeffrey W. Reep , Amir Caspi

Spectroscopic observations of a solar limb flare recorded by SUMER on SOHO reveal, for the first time, hot fast magnetic reconnection outflows in the corona. As the reconnection site rises across the SUMER spectrometer slit, significant…

Astrophysics · Physics 2018-06-19 Tongjiang Wang , Linhui Sui , Jiong Qiu

Simultaneous observations of explosive chromospheric evaporation are presented using data from the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Coronal Diagnostic Spectrometer (CDS) onboard SOHO. For the first time,…

On April 17, 2024, the third successful Hi-C sounding rocket flight, Hi-C Flare, recorded coronal images in Fe XXI 129 A emission from 11 MK plasma during the post-maximum phase of an M1.6-class solar flare, achieving unprecedented spatial…

Plumes are one of the most ubiquitous features seen at the limb in polar coronal holes and are considered to be a source of high density plasma streams to the fast solar wind. We analyze STEREO observations of plumes and aim to reinterpret…

Solar and Stellar Astrophysics · Physics 2010-08-31 Scott W. McIntosh , Davina E. Innes , Bart De Pontieu , Robert J. Leamon

We analyze a Chandra-HETGS observation of the single G-type giant HR 9024. The high flux allows us to examine spectral line and continuum diagnostics at high temporal resolution, to derive plasma parameters (thermal distribution,…

Astrophysics · Physics 2007-05-23 Paola Testa , David Garcia-Alvarez , Fabio Reale , David Huenemoerder

{Chromospheric evaporation is a key process in solar flares that has extensively been investigated using the spectroscopic observations. However, direct soft X-ray (SXR) imaging of the process is rare, especially in remote brightenings…

Solar and Stellar Astrophysics · Physics 2015-06-16 Q. M. Zhang , H. S. Ji

Magnetic reconnection is the key mechanism for energy release in solar eruptions, where the high-temperature emission is the primary diagnostic for investigating the plasma properties during the reconnection process. Non-thermal broadening…

Solar and Stellar Astrophysics · Physics 2022-11-15 Chengcai Shen , Vanessa Polito , Katharine K. Reeves , Bin Chen , Sijie Yu , Xiaoyan Xie

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

Microflares have been considered to be among the major energy input sources to form active solar corona. To investigate the response of the low atmosphere to events, we conducted an ALMA observation at 3 mm coordinated with IRIS and Hinode…

Solar and Stellar Astrophysics · Physics 2021-12-08 Toshifumi Shimizu , Masumi Shimojo , Masashi Abe

Understanding the physical processes that trigger solar flares is paramount to help with forecasting space weather and mitigating the effects on our technological infrastructure. A previously unknown phenomenon was recently identified in…

The Reuven Ramaty High Energy Solar Spectroscopy Imager (RHESSI) has obtained the first high-resolution measurements of nuclear de-excitation lines produced by energetic ions accelerated in a solar flare, a GOES X4.8 event occurring on 23…

This paper presents a detailed study of excess line broadening in EUV emission lines during the impulsive phase of a C-class solar flare. In this work, which utilizes data from the EUV Imaging Spectrometer (EIS) onboard Hinode, the…

Solar and Stellar Astrophysics · Physics 2012-02-09 Ryan O. Milligan

We explore the temporal relationship between microwave/HXR emission and Doppler velocity during the impulsive phase of a solar flare on 2014 October 27 (SOL2014-10-27), which displays a pulse on the light curves in microwave (34 GHz) and…

Solar and Stellar Astrophysics · Physics 2017-05-24 Dong Li , Zongjun Ning , Yu Huang , Qingmin Zhang

Observations of solar flares at sub-THz frequencies (mm and sub-mm wavelengths) over the last two decades often show a spectral component rising with frequency. Unlike a typical gyrosynchrotron spectrum decreasing with frequency, or a weak…

Solar and Stellar Astrophysics · Physics 2018-12-05 E. P. Kontar , G. G. Motorina , N. L. S. Jeffrey , Y. T. Tsap , G. D. Fleishman , A. V. Stepanov

We report a NuSTAR observation of a solar microflare, SOL2015-09-01T04. Although it was too faint to be observed by the GOES X-ray Sensor, we estimate the event to be an A0.1 class flare in brightness. This microflare, with only 5 counts…

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