| Presentation Title: | Joint Microwave and X-ray Observations of Supra-Arcade Downflows Impacting the Loop-Top and Above-Loop-Top Regions |
| Author(s): | Yuqian Wei
Bin Chen
Sijie Yu
Xiaoyan Xie
Yixian Zhang |
Abstract:
Supra-arcade downflows (SADs) are dynamic, sunward-moving plasma voids observed in the solar corona above flare arcades. Despite frequent observations, the mechanisms driving SADs and their impact on the flaring corona remain subjects of debate. In this study, we present joint microwave and X-ray observations of an M2.2 west limb flare on May 11, 2022. This event featured two episodes of SADs, with the relatively rare occurrence during the main impulsive phase and the more common post-impulsive phase. We present four key findings from our study on the interaction between the supra-arcade downflows (SADs) and the flare arcades:
1. The interaction between SADs and the flare arcade results in the transverse displacement of both microwave and Extreme Ultraviolet (EUV) emissions.
2. We note a correlation between the arrival of SADs and enhancements in the microwave light curve from 5-13 GHz, accompanied by thermal X-ray emissions in the loop-top region with an average 35-second delay relative to the microwave emissions.
3. In certain instances observed in (2), spectral hardening on the optically thin side of the microwave spectrum occurs as SADs reach a certain height.
4. The frequency of SADs throughout the flare's main and post-impulsive phases correlates with periodic enhancements in microwave and soft X-ray emissions.
These findings highlight the significant influence of SADs on the dynamics and electron population in the loop-top and above-loop-top regions of solar flares.