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Title: Electron distribution functions in solar flares from combined X-ray and extreme-ultraviolet observations

Simultaneous solar flare observations with SDO and RHESSI provide spatially resolved information about hot plasma and energetic particles in flares. RHESSI allows the properties of both hot (≳8 MK) thermal plasma and non-thermal electron distributions to be inferred, while SDO/AIA is more sensitive to lower temperatures. We present and implement a new method to reconstruct electron distribution functions from SDO/AIA data. The combined analysis of RHESSI and AIA data allows the electron distribution function to be inferred over the broad energy range from 0.1 keV up to a few tens of keV. The analysis of two well-observed flares suggests that the distributions in general agree to within a factor of three when the RHESSI values are extrapolated into the intermediate range 1-3 keV, with AIA systematically predicting lower electron fluxes. Possible instrumental and numerical effects, as well as potential physical origins for this discrepancy, are discussed. The inferred electron distribution functions in general show one or two nearly Maxwellian components at energies below ∼15 keV and a non-thermal tail above.
Authors:
 [1] ;  [2]
  1. Institute of 4D Technologies, School of Engineering, University of Applied Sciences and Arts Northwestern Switzerland, 5210 Windisch (Switzerland)
  2. SUPA, School of Physics and Astronomy, University of Glasgow, G12 8QQ (United Kingdom)
Publication Date:
OSTI Identifier:
22348469
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 779; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; CHROMOSPHERE; DATA; DISTRIBUTION; DISTRIBUTION FUNCTIONS; ELECTRONS; EXTREME ULTRAVIOLET RADIATION; GAMMA RADIATION; HOT PLASMA; KEV RANGE; PARTICLES; SOLAR FLARES; SUN; X RADIATION