CME影响下L1点附近等离子体及共生微波爆发的射电辐射机制研究

CME在产生和发展过程中与日冕和行星际介质相互作用并发出不同波长的射电辐射．在研究了无CME时空间等离子体的各种辐射机制基础上，统计分析了1999年2月至1999年8月期间有较大的CME发生情况下，在CME影响下L1拉格朗日点附近等离子体参数发生变化后的射电辐射机制．分析结果表明，其射电辐射机制主要是轫致辐射、微量的回旋辐射和更加微弱的复合辐射．此外，分析讨论了1999年2月至1999年8月期间与CME共生的太阳微波爆发．分析结果表明，与CME共生的是微波逐渐型爆发、尖峰爆发，其辐射机制主要是轫致辐射、回旋共振辐射、等离子体辐射及电子回旋脉泽辐射．

Study on the Radiation Mechanism of Plasmas Near L1 Point Affected by CMEs and the Associated Microwave Bursts

Coronal mass ejections are large-scale magnetic structures expelled from the sun due to MHD processes involving interaction between plasmas and magnetic field in closed field regions. Radiation with different wavelength is emitted because of reciprocity of coronal mass ejections with corona and interplanetary medium. A comprehensive survey is made on coronal mass ejections occurred from February 1999 to August 1999 which were observed by LASCO and the ground radio spectrometer in Purple Mountain Observatory and Yunnan Observatory. Special attentions are focused on the emission mechanisms of space plasmas near L1(the first Lagrange point of solarearth system) which are affected by very large coronal mass ejections. Statistical analysis is also made based on the study of the radiation mechanisms of space plasmas during quiet sun period. The results show that the dominating radiation mechanisms are bremsstrahlung, a small quantity of cyclotron radiation and a less quantity of recombination radiation. Moreover, solar radio microwave bursts which accompany with coronal mass ejections during February 1999 to August 1999 are analyzed. The findings indicate that they are gradual bursts and spike bursts. The dominating radiation mechanisms of the solar radio microwave bursts are bremsstrahlung, cyclotron resonant radiation, plasmas radiation and electronic cyclotron maser radiation.