X-ray eruptive structures associated with small flares Original Research Article

We searched for X-ray eruptive structures above the flare loops, whose soft X-ray flux at the peak phase ranges from class A to C in the GOES classification, using the Yohkoh soft X-ray observations in 1996 when the background corona was very weak. We found 12 plasmoid-like or loop-like ejecta out of 43 flares studied. Existence of these eruptive structures implies that the magnetic reconnection model, which was strongly supported by Yohkoh observations of flares of a narrow range of X-ray peak flux, can explain the solar flares covering more than five orders of magnitude in the soft X-ray flux. We also found that the projected outgoing velocities of the ejecta are systematically slower in small flares than in large flares.