Energy spectrum of X-ray flares associated with sunspot groups of different classes in three solar cycles

Abstract

The integral energies of flares associated with active regions of different classes of sunspot groups were calculated on the basis of direct measurements of X-ray fluxes from flares (1–8A, GOES) for three solar cycles (1977–2007). The integral energy spectra were constructed, and their indices β were calculated for flares in active regions of each class. It was established that the value of parameter β is different for the active regions of different classes. A positive correlation between this parameter and the 11-year cycle (the Wolf number) was revealed for each class. Parameter β is related to the 22-year magnetic cycle. Our results can be used in the dynamo and flare theories.