  Multi-instrument observations of two filament eruptions on 24 February and 11
May 2011 suggest the following updated scenario for eruptive flare, CME and
shock wave evolution. An initial destabilization of a filament results in
stretching out of magnetic threads belonging to its body and rooted in the
photosphere along the inversion line. Their reconnection leads to i) heating of
parts of the filament or its environment, ii) initial development of the flare
arcade cusp and ribbons, and iii) increasing similarity of the filament to a
curved flux rope and its acceleration. Then the pre-eruption arcade enveloping
the filament gets involved in reconnection according to the standard model and
continues to form the flare arcade and ribbons. The poloidal magnetic flux in
the curved rope developing from the filament progressively increases and forces
its toroidal expansion. This flux rope impulsively expands and produces an MHD
disturbance, which rapidly steepens into a shock. The shock passes through the
arcade expanding above the filament and then freely propagates ahead of the CME
like a decelerating blast wave for some time. If the CME is slow, then the
shock eventually decays. Otherwise, the frontal part of the shock changes into
the bow-shock regime. This was observed for the first time in the 24 February
2011 event. When reconnection ceases, the flux rope relaxes and constitutes the
CME core-cavity system. The expanding arcade develops into the CME frontal
structure. We also found that reconnection in the current sheet of a remote
streamer forced by the shock's passage results in a running flare-like process
within the streamer responsible for a type II burst. The development of dimming
and various associated phenomena are discussed.
