The Astrophysical Journal recently published an article performed by Dr. ZHOU Xingping from Sichuan Normal University, Professor LIANG Hongfei from Yunnan Normal University, Professor SHEN Yuandeng and his co-authors from Yunnan Observatories by using multi-wavelength observations taken by the Solar Dynamic Observatory (SDO). The study presented the observations of three recurrent quasiperiodic fast-propagating (QFP) wave trains along the same open magnetic field lines from the same eruption source region.

QFP wave trains are usually observed in the low corona using extreme ultraviolet images, and can be divided into two categories including narrow and broad QFP wave trains propagating along and perpendicular to magnetic field, respectively. Both types are tightly associated with periodic pulsations in flares, but their excitation mechanisms are still an open question although some candidate scenarios have been proposed. As suggested in a recent review article written by Shen et al. 2022, SoPh, 297, 20, QFP wave trains and flare periodic pulsations might manifest two different aspects of the same physical process.

Dr. ZHOU, Prof. LIANG, Prof. SHEN and their co-authors reported the observation of three QFP wave trains in the same active region and propagate outwardly along the same path. The authors found that the wave trains propagated at fast speed of about 1,000 kilometers per second, started at the same times of the energy pulses in the accompany flare. More interestingly, the QFP wave trains have the same periods with the quasi-periodic pulsations in the accompanying flare.

In addition, it is also found that the phase speeds of the QFP wave trains are the same with their group speed. These observational results suggest that the observed QFP wave trains are most probably excited by the intermittent energy release process in the accompanying flare, rather than the dispersion of the waveguide. Finally, the authors use the technique of coronal seismology to derive the magnetic field strength of the waveguide and the energy flux carried by the wave train. These studies show that QFP wave train is a good tool for diagnosing the physical property of the coronal plasma.

Contact:
SHEN Yuandeng
Yunnan Observatories, CAS
Email: ydshen@ynao.ac.cn