Chen, Bin, Bastian, Timothy S., Shen, Chengcai, Gary, Dale E., Krucker, Säm, and Glesener, Lindsay. 2015. "Particle acceleration by a solar flare termination shock." Science 350:1238-1242. https://doi.org/10.1126/science.aac8467
Solar flares—the most powerful explosions in the solar system—are also efficient particle accelerators, capable of energizing a large number of charged particles to relativistic speeds. A termination shock is often invoked in the standard model of solar flares as a possible driver for particle acceleration, yet its existence and role have remained controversial. We present observations of a solar flare termination shock and trace its morphology and dynamics using high-cadence radio imaging spectroscopy. We show that a disruption of the shock coincides with an abrupt reduction of the energetic electron population. The observed properties of the shock are well reproduced by simulations. These results strongly suggest that a termination shock is responsible, at least in part, for accelerating energetic electrons in solar flares.