RHESSIHard X‐Ray Imaging Spectroscopy of Extended Sources and the Physical Properties of Electron Acceleration Regions in Solar Flares

2008 ◽  
Vol 673 (1) ◽  
pp. 576-585 ◽  
Author(s):  
Yan Xu ◽  
A. Gordon Emslie ◽  
G. J. Hurford
2021 ◽  
Author(s):  
Andrea Francesco Battaglia ◽  
Jonas Saqri ◽  
Ewan Dickson ◽  
Hualin Xiao ◽  
Astrid Veronig ◽  
...  

<p>With the launch and commissioning of Solar Orbiter, the Spectrometer/Telescope for Imaging X-rays (STIX) is the latest hard X-ray telescope to study solar flares over a large range of flare sizes. STIX uses hard X-ray imaging spectroscopy in the range from 4 to 150 keV to diagnose the hottest temperature of solar flare plasma and the related nonthermal accelerated electrons. The unique orbit away from the Earth-Sun line in combination with the opportunity of joint observations with other Solar Orbiter instruments, STIX will provide new inputs into understanding the magnetic energy release and particle acceleration in solar flares. Commissioning observations showed that STIX is working as designed and therefore we report on the first solar microflare observations recorded on June 2020, when the spacecraft was at 0.52 AU from the Sun. STIX’s measurements are compared with Earth-orbiting observatories, such as GOES and SDO/AIA, for which we investigate and interpret the different temporal evolution. The detected early peak of the STIX profiles relative to GOES is due either by nonthermal X-ray emission of accelerated particles interacting with the dense chromosphere or the higher sensitivity of STIX toward hotter plasma.</p>


1997 ◽  
Vol 49 (4) ◽  
pp. 445-452 ◽  
Author(s):  
Hisamitsu Awaki ◽  
Katsuji Koyama ◽  
Hironori Matsumoto ◽  
Hiroshi Tomida ◽  
Takeshi Tsuru ◽  
...  

2014 ◽  
Vol 10 (S312) ◽  
pp. 36-38
Author(s):  
Junfeng Wang

AbstractThe circum-nuclear region in an active galaxy is often complex with presence of high excitation gas, collimated radio outflow, and star formation activities, besides the actively accreting supermassive black hole. The unique spatial resolving power of Chandra X-ray imaging spectroscopy enables more investigations to disentangle the active galactic nuclei and starburst activities. For galaxies in the throes of a violent merging event such as NGC6240, we were able to resolve the high temperature gas surrounding its binary active black holes and discovered a large scale soft X-ray halo.


2017 ◽  
Vol 13 (S335) ◽  
pp. 90-93
Author(s):  
P. A. Gritsyk ◽  
B. V. Somov

AbstractUsing the appropriate kinetic equation, we considered the problem of propagation of accelerated electrons into the solar corona and chromosphere. Its analytical solution was used for modelling the M7.7 class limb flare occurred on July 19, 2012. Coronal above-the-loop-top hard X-Ray source was interpreted in the thin-target approximation, the foot-point source - in the thick-target approximation with account of the reverse-current electric field. For the foot-point source we found a good accordance with the RHESSI observations. For the coronal source we also got very accurate estimate of the power-law spectral index, but significant differences between the modelled and observed hard X-ray intensities were noticed. The last discrepancy was solved by adding the coronal magnetic trap model to the thin target model. The former one implies that the trap collapses in two dimensions, locks and accelerates particles inside itself. In our report, we confirm an existence and high efficiency of the electron acceleration in collapsing magnetic traps during solar flares. Our new results represent (e.g. for RHESSI observations) the theoretical prediction of the double step particle acceleration in solar flares, when the first step is the acceleration in reconnection area and the second one – the acceleration in coronal trap.


1972 ◽  
Vol 14 ◽  
pp. 822-823
Author(s):  
S. R. Kane

Using the measurements of impulsive solar X-rays made with the OGO-5 satellite to identify the flash phase electron acceleration in solar flares of Hα-importance ≲ 1, the satellite and ground based observations are analyzed to study the origin of the different groups of non-thermal electrons responsible for the impulsive X-ray, impulsive microwave, type III radio and interplanetary electron emission.


2010 ◽  
Author(s):  
Christoph Braig ◽  
Peter Predehl

1988 ◽  
Author(s):  
David H. Lumb ◽  
Andrew D. Holland

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