Network flares as agents of coronal heating

Abstract

Network flares are small heating events occurring outside the active regions, mostly over the network junctions, where coronal bright points are most likely to form. The amount of thermal energy released into the flaring plasma is of the order of 10 26−27 ergs per event and then can be classed as micro-flares when compared to very large solar flares (10 32 ergs). In this paper we present our efforts to improve our knowledge about the network flaring ratio in X-rays, which now is estimated to be approximately 8000 events per day over the whole Sun, and gives the total rate of energy released in these events 8 × 10 25 ergs s −1. This value is about one order of magnitude less than the energy rate needed to heat up the quiescent corona. However the number distribution of events with energy shows the prevalence of weak flares strong enough to expect that the heating requirements of the quiescent corona could be achieved when extrapolating the distribution below the detectability treshold.