Analysis of a solar eruptive event on November 4, 2001, using CORONAS-F/SPIRIT data

We analyze large-scale solar activity following the eruption of a very powerful, geoeffective coronal mass ejection in the 23rd solar cycle, observed at 175, 284, and 304 Å on November 4, 2001, using data from the CORONAS-F/SPIRIT telescope. In particular, we have shown that the restructuring of the magnetic field above the eruption center was accompanied by the formation of a multicomponent post-eruptive arcade, which was observed in all three bands over many hours and had an extent of the order of 0.5R_⊙. Two kinds of dimmings were observed, i.e., compact dimmings on either side of this arcade and channeled dimmings along some extended features beyond the active region. The intensity in the dimmings decreased by several tens of percent. The enhanced emission observed at the top of the post-eruptive arcade can be due to energy release in the course of magnetic reconnection high in the corona at the relaxation stage of the perturbed magnetic field to a new equilibrium state with a closed configuration. It can also be due to an enhanced emission measure because of the oblique direction of the line of sight crossing both loop tops and footpoint regions. The spatial coincidence of the main dimmings in lines corresponding to different temperatures indicates that a plasma outflow from the transition region and coronal structures with opened field lines are responsible for these dimmings. Variations in the plasma temperature associated with coronal mass ejections probably play an important role for some dimmings, which appear different in different lines.