Primary Research on a Complex Solar Radio Burst and its Characteristics of Microwave Sources

A very complex outstanding solar radio burst was observed with the wide-band spectrometer of NAOC on October 19,2001.This burst was characterized by a broader band (decameter to dcetimeter) burst followed by an more intense narrow-band burst at the lower frequencies (decimetric).NoRH (Nobeyama Radio Heliograph) observations about this event at 17 and 34 GHz showed that the cofiguration of radio sources included three sources,i.e.,a pre-existing source,a main source,and a disturbing source.The emission time profiles of these three sources were essentially different.The pre-existing source should be the manifestation of the heating process of the flare,and should be related to the complex component of the radio burst.The main source should be related to the continua of the radio burst.The disturbing source should be the trigger of this burst.Combining the data of NoRH,the evolution of microwave sources,as well as the relation between the sources evolution and the global features of the radio emissions are studied.Combining the data of MDI (Michelson Doppler Imager),we conclude that the pre-existing source should be near the feet of the coronal loop and the main source shoule be near the top of the loop or at least near the loop leg.Furthermore,the very slow moving of the main source has been found,it may be related to the formation of CME associated with this event.