Solar Flares and the Axion Quark Nugget Dark Matter Model

Abstract

We advocate the idea that the nanoflares conjectured by Parker long ago to resolve the corona heating problem, may also trigger the larger solar flares. The arguments are based on the model where emission of extreme ultra violet (EUV) radiation and soft x-rays from the Sun are powered externally by incident dark matter particles within the Axion Quark Nugget (AQN) Dark Matter Model. The corresponding annihilation events of the AQNs with the solar material are identified with nanoflares. This model was originally invented as a natural explanation of the observed ratio $\Omega_{\rm dark} \sim \Omega_{\rm visible}$ when the DM and visible matter densities assume the same order of magnitude values. This model gives a very reasonable intensity of EUV radiation without adjustments of any parameters in the model. When the same nuggets enter the regions with high magnetic field they serve as the triggers igniting the magnetic reconnections which eventually may lead to much larger flares. Technically, the magnetic reconnection is ignited due to the shock wave which inevitably develops when the dark matter nuggets enter the solar atmosphere with velocity $v_{\rm AQN}\sim ~600~ {\rm km/s}$ which is much higher than the speed of sound $c_s$, such that the Mach number $M=v_{\rm AQN}/c_s\gg 1$. These shock waves generate very strong and very short impulses expressed in terms of pressure $\Delta p/p\sim M^2$ and temperature $\Delta T/T\sim M^2$ in vicinity of (would be) magnetic reconnection area. The mechanism is consistent with the observed scaling of the flare distribution $dN\sim W^{-\alpha}dW$ as a function of the flare's energy $W$. We also speculate that the same nuggets may trigger the sunquakes which are known to be correlated with large flares.