Disentangling Thermal and Abundance Characteristics in a Solar Flare Using SDO/AIA, Hinode/XRT, and MinXSS-1 Observations

TL;DR

This study uses multi-instrument observations to analyze the thermal and compositional properties of a solar flare, revealing distinct heating mechanisms and the importance of combined spectral and spatial diagnostics for understanding solar phenomena.

Contribution

It provides new insights into the thermal structure and abundances in a solar flare by combining data from Hinode, SDO/AIA, and MinXSS-1, highlighting differences in plasma detection and the significance of simultaneous diagnostics.

Findings

The plasma cloud is too tenuous for detection in MinXSS-1 spectra.

Different temperature profiles indicate separate heating mechanisms.

Coronal and photospheric abundance models show significant differences.

Abstract

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 but hot plasma cloud located above the flare loops. The flare loops and plasma cloud exhibit independent temperature profiles as a function of time, implying different heating mechanisms are present in these structures. We interpret the plasma cloud as an eruptive filament directly heated in the corona via magnetic reconnection that occurs when a rising filament interacts with this eruptive filament. Previous disk-integrated solar soft X-ray spectral measurements of this flare using the Miniature X-ray Solar Spectrometer CubeSat-1 (MinXSS-1) inferred coronal abundances at the flare peak. However, MinXSS synthetic spectra from AIA observations show that the plasma cloud is too tenuous to be detected in MinXSS-1 and thus the coronal abundances of low FIP elements must be in emission from the flare loops. Furthermore, we demonstrate the non-negligible differences in differential emission measures (DEMs) between coronal and photospheric abundance models. These results highlight the importance of instruments capable of simultaneous spectral and spatial diagnostics during large-scale solar events. Such coordinated measurements would enable more accurate thermal and compositional analyses and deeper insight into the underlying physical mechanisms.