Flare frequency-size distributions for individual active regions

It is well known that the size (peak count rate of emission, or inferred en ergy) distribution of flares observed on the Sun follows a power law. Howev er, the distributions that are constructed include flares from different ac tive regions that have a variety of physical properties. In this paper cumu lative peak count rate distributions are constructed for individual active regions using events listed in the WATCH solar X-ray burst catalog. The ind ividual distributions are found to be consistent with the distribution cons tructed from events in all active regions named in the catalog. This result suggests that the flare power-law size distribution reflects an intrinsic property of the flare mechanism and is not a product of the distributions o f physical parameters between active regions. The result is consistent with the avalanche model for flares and more generally argues against macroscop ic flare models.