Frontiers in Astronomy and Space Sciences (Sep 2023)

Multi-wavelength observations and modeling of a microflare: constraining non-thermal particle acceleration

  • Vanessa Polito,
  • Vanessa Polito,
  • Marianne Peterson,
  • Lindsay Glesener,
  • Paola Testa,
  • Sijie Yu,
  • Katharine K. Reeves,
  • Xudong Sun,
  • Jessie Duncan

DOI
https://doi.org/10.3389/fspas.2023.1214901
Journal volume & issue
Vol. 10

Abstract

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In this work we analyze a small B-class flare that occurred on 29 April 2021 and was observed simultaneously by the Interface Region Imaging Spectrograph (IRIS) and the Nuclear Spectroscopic Telescope Array (NuSTAR) X-ray instrument. The IRIS observations of the ribbon of the flare show peculiar spectral characteristics that are typical signatures of energy deposition by non-thermal electrons in the lower atmosphere. The presence of the non-thermal particles is also confirmed directly by fitting the NuSTAR spectral observations. We show that, by combining IRIS and NuSTAR multi-wavelength observations from the corona to the lower atmosphere with hydrodynamic simulations using the RADYN code, we can provide strict constraints on electron-beam heated flare models. This work presents the first NuSTAR, IRIS and RADYN joint analysis of a non-thermal microflare, and presents a self-consistent picture of the flare-accelerated electrons in the corona and the chromospheric response to those electrons.

Keywords