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

Abstract We investigate the thermal properties of a solar flare by the observations of the soft X-ray Telescope on board Hinode and the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory. 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 that 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; thus, the coronal abundances of low first ionization potential elements must be in emission from the flare loops. Furthermore, we demonstrate the nonnegligible differences in differential emission measures 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.