Thermal Structure of Supra-arcade Downflows and Flare Plasma Sheets
Abstract
We use Hinode/XRT and SDO/AIA data to determine the thermal structure of supra arcade downflows as well as the surrounding plasma sheet. Using the multiple filters and broad temperature coverage provided by the combination of these two telescopes, we construct DEMs in the fan plasma and the supra-arcade downflows. Several models have indicated that the plasma inside the supra-arcade downflows should be significantly hotter than the surrounding plasma, but about an order of magnitude less dense. However, we find that the temperatures of the plasma within the downflows are either roughly the same as or lower than the surrounding fan plasma, with only one exception. We also compare the thermal structure of the supra-arcade plasma with calculations of the divergence of the velocity of the plasma in the sheet in order to locate evidence of adiabatic cooling and heating. The velocity fields are calculated using local correlation tracking applied to high-resolution sequences of AIA images. We find preliminary evidence that diverging velocity fields are cooler and less dense than the surrounding plasma.
- Publication:
-
AAS/Solar Physics Division Abstracts #44
- Pub Date:
- July 2013
- Bibcode:
- 2013SPD....4430404R