Related results were published in the Astrophysical Journal.

The researchers found that microwave source shows a recurrent decrease and increase during its overall upward motion; it shows a kind of recurrent contraction and expansion. The time period of the recurrent contraction and expansion corresponds to the period of post-contraction oscillation of EUV loops, and the oscillatory motions are closely correlated with four microwave/hard X-ray peaks that unusually increased nonthermal emission levels by several times.

“In the study, we investigate the filament with bidirectional material transport, and two new formed hot channel magnetic flux ropes, they activated and powered the onset of the flare”, said Dr. SHEN.

For the process of the energy release of the flare, they found that the formation of magnetic flux ropes is due to the continuous magnetic reconnection. And the radio and X-ray coronal sources in 25–50 keV energy bands are located at the top of the flare loop, which is regarded as the place of particle acceleration. In addition, the spectral evolution of the flare shows a soft–hard–harder behavior, which is suggested a continuing acceleration of particles while they are trapped in flaring loops.

“According to our results, the contraction of the peripheral magnetic loops is more likely due to the vortex and sink flows generated by an upward erupting magnetic flux rope rather than a coronal implosion, on the other hand, the EUV waves crossing and hitting the peripheral loops further lead to their contraction to arrive at a new equilibrium after the eruption, said Dr. SHEN.

The researchers will provide more insight into the physics of dynamic coronal magnetic field and particle acceleration during solar flares. It is also important implications for understanding the energy release of solar flares.

Contact: SHEN Jinhua

Xinjiang Astronomical Observatory, Chinese Academy of Sciences

Email:shenjh@xao.ac.cn