Elementary Energy Release Events in Solar Flares

Abstract

Most theoretical investigations of particle acceleration during solar flares cannot be applied to observations for detailed study of the time evolution. We propose a phenomenological model for turbulence evolution and stochastic particle acceleration that links observations to the energy release and particle acceleration through two coefficients characterizing particle interactions with turbulent electromagnetic fields. In the linear regime the particle distribution does not affect the turbulence energy cascade. It is shown that electron acceleration critically depends on the intensity of small-scale turbulence and an impulsive non-thermal component only appears near the peak of the gradually evolving turbulence intensity. The model naturally reproduces the soft-hard-soft pattern of hard X-ray pulses, and we attribute the observed change in flux and spectral index correlation from the rise to decay phase of some pulses to changes in the background plasma. Detailed modeling of well-observed individual events will probe the energy release processes.

12 pages, 2 figures, Accepted by ApJL

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Cited by in corpus (11)

• Implications of X-ray Observations for Electron Acceleration and Propagation in Solar Flares
• Propagation of Alfvénic Waves From Corona to Chromosphere and Consequences for Solar Flares
• M Dwarf Flare Continuum Variations on One-Second Timescales: Calibrating and Modeling of ULTRACAM Flare Color Indices
• Flare Ribbon Energetics in the Early Phase of an SDO Flare
• Impulsive Phase Coronal Hard X-ray Sources in an X3.9 Class Solar Flare
• Thermal to Nonthermal Energy Partition at the Early Rise Phase of Solar Flares
• The impulsive phase of magnetar giant flares: assessing linear tearing as the trigger mechanism
• Direct observation of the energy release site in a solar flare by SDO/AIA, Hinode/EIS and RHESSI
• Relationship between Hard and Soft X-ray Emission Components of a Solar Flare
• Elementary Energy Release Events in Flaring Loops: Effects of Chromospheric Evaporation on X-rays
• Onset of Electron Acceleration in a Flare Loop