1990年5月23日在3.2厘米波段射电爆发中的准周期结构

QUASI-PERIODIC STRUCTURES SUPERIMPOSED UPON A LARGE RADIO BURST AT 3.2CM WAVELENGTH ON MAY 23, 1990

本文简要地叙述1990年5月23日在3.2cm波段大爆发上迭加有丰富的准周期振荡结构Fs,平均周期为1.5秒左右,Fs的调制度在(2—5)%间.初步分析表明射电流量与准周期振荡出现的重复率成线性关系.与Kaufmann在毫米波段的观测结果相一致.这种振荡可能是由于磁流管的MHD振荡导致磁场的周期变化,从而使回旋同步辐射受到准周期调制的结果.

This paper describes a lot of quasi-periodic structures superimposed upon a large solar radio burst which was observed at 3.2 cm wavelength on May 23, 1990. This large burst corresponded to a M8.7/1B flare. The average period of these quasi-periodic structures is about 1.5s and their relative amplitudes range from 2% to 5%. A preliminary analysis shows that there exsits a linear relation between the flux and repetition of the quasi-periodic structures. This result is consistent with that obtained by Kaufmann in mm wavelengths. The authors suggest that these quasi-periodic structures may be the modulated gyro-syn-chrotron emissions due to a MHD wave oscillating along the corresponding magnetic field lines.