3D Simulations of Dynamic Coronal Loops
Abstract
Active-region coronal loops have been observed in EUV by EIT/SOHO and TRACE and in soft X-ray by SXT/Yohkoh for many years. Although the loops observed by EIT and Yohkoh appear to be in a quasi-steady state, TRACE is able to capture their dynamic nature at high resolution, showing their brightening and fading in time. The activity, as well as the characteristics of the emissions, is believed to be strongly related to plasma heating, the major unknown factor in the energy equation and an outstanding problem in solar physics. We have constructed the thermal structure of an active region in 3D for several heating models. One of them results in a highly dynamic structure without settling into a quasi-steady state. Each flux tube has its own time variation characteristics in temperature and density. We then computed the time dependent EUV emissions of the entire region, and found that it appears to closely resemble the images seen in the TRACE movies; namely, brightening and fading of thin, EUV emitting plasma loops of nearly uniform cross section. Quantitative comparison between the results of our simulation and EIT/SXT measurements will be made.*This research is supported by the Sun-Earth Connection Theory Program of NASA.
- Publication:
-
AAS/Solar Physics Division Meeting #37
- Pub Date:
- June 2006
- Bibcode:
- 2006SPD....37.1704M