C31

Presentation Title:	Spectroscopic Observations of Supra-Arcade Downflows (SADs)
Author(s):	Ryan French, Maria Kazachenko, Katharine Reeves, Teodora Mihailescu

Abstract:

Despite their somewhat-frequent appearance in EUV imaging of off-limb flares, the origins of Supra-Arcade Downflows (SADs) remain a mystery. Appearing as dark, tendril-like downflows above growing flare loop arcades, SADs themselves are yet to be tied into the standard model of solar flares. The uncertainty of their origin is, in part, due to a lack of spectral observations, with the last published SAD spectral observations dating back to the SOHO/SUMER era. In this work, we present new observations of Supra-Arcade Downflows within an M-class solar flare, observed by the Hinode EUV Imaging Spectrometer (EIS) and Solar Orbiter’s Spectrometer Telescope for Imaging X-rays (STIX). We measure Fe XXIV Doppler downflows and non-thermal velocities exceeding those of the surrounding hot flare fan, with evidence of diverging SAD flows above the flare arcade. Finally, we find evidence of fast downflow components within the line-of-sight, albeit far slower than the 1000 km/s downflows reported from the SUMER era.

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