RHESSI and TRACE Observations for the Impulsive Flare Loops

Abstract

After summarizing the geometric relationship of the RHESSI flare X-ray sources with the TRACE flare loops, and the motion modes of RHESSI flare X-ray sources, we concentrate on the newly discovered downward motion of flare looptop X-ray source. In particular, we present a new argument for the flare loop shrinkage during the impulsive phase: TRACE 195 Å loop shrinkage. The temporal behavior of 195 Å loop shrinkage and its magnitude are consistent with that revealed from the RHESSI X-ray sources. Further study shows that the TRACE 195 Å loop shrinkage is in the form of oscillation, with a period of about 150 s and an amplitude of about 300 km. We discuss this oscillatory shrinkage with respect to a numerical simulation of reconnection model.