Observational Characteristics Extraction And Parameters Estimation Of Microwave Spike Emission In Solar Flare

Solar radio bursts are usually accompanying with solar flares. The complicated radio spectrum detected in solar radio bursts contained a lot of important information on their source region including physical environment and emission mechanism. Especially, because of their morphologic features of short duration, rapid frequency drift, complicated types and so on, the microwave fine structures could bring out rich important information on the source region such as the complicated configuration of magnetic reconnection, the movement of energetic particle, etc. Because of their extremely high brightness temperature, short duration and narrow bandwidth, microwave spike emissions are a kind of typical short timescale fine structures in solar radio bursts. It is generally suggested that the study of these fine structures may give some insight into the elementary processes taking place in the source regions of solar flares.The solar broadband radio dynamic spectrometer (SBRS) of China has been put into routine observations in recent years. Due to its high temporal resolution (about 1ms) and high spectral resolution (1.37MHz), a large amount of microwave burst fine structures data with high resolution and high sensitivity have been detected, including a lot of microwave spike emissions. An important work is the observational characteristics extraction of microwave spike emissions from a large amount of raw observational data. In this thesis, for the radio spike event observed on October 27, 2003, we focus to study the methods of characteristics extraction of its microwave spike emissions in detail. A set of algorithm including filtering the background emissions in spectrum by Fourier Transform and searching the microwave spike features by computer automatically was designed and programmed using IDL language. As a result, 420 microwave spike emissions were extracted. The time profile of each single spike was fitted and analyzed. In particular, we determined the e-folding rise and decay times corresponding to the ascending and decaying parts of the timeprofile, respectively. Several important correlations were studied and compared with the results in earlier literature, i.e. those between duration and frequency, e-folding rise time and decay time, e-folding decay time and duration, and e-folding decay time and peak flux. Finally, the parameters of source region were estimated and the possible decaying mechanism was discussed.