RHESSI Observations of a Simple Large X-Ray Flare on 2003 November 3

We present data analysis and interpretation of a simple X-class flare observed with RHESSI on 2003 November 3. In contrast to other X-class flares observed previously, this flare shows a very simple morphology with well-defined looptop (LT) and footpoint (FP) sources. The almost monotonic upward motion of the LT source and increase in separation of the two FP sources are consistent with magnetic reconnection models proposed for solar flares. In addition, we find that the source motions are relatively slower during the more active phases of hard X-ray emission; the emission centroid of the LT source shifts toward higher altitudes with the increase of energy; and the separation between the LT emission centroids at two different photon energies is anticorrelated with the FP flux. Nonuniformity of the reconnecting magnetic fields could be a possible explanation of these features.