摘要
利用中国科学院国家天文台太阳射电动态频谱仪(1.0～2.0GHz和2.6～3.8GHz)在1998年9月23日观测到伴生Ⅲ型爆发群和Ⅰ型噪爆的分米波Ⅳ型爆发,着重讨论在Ⅳ型爆发衰减相产生的Ⅰ型噪爆,这个噪爆由许多Ⅰ型爆发组成,每个Ⅰ型爆的寿命约为100～300ms,总持续时间大于11min。噪爆辐射的圆偏振度大于Ⅳ型连续辐射爆发,平均偏振度约为64%。这个Ⅰ型噪爆可能类似于高偏振的Ⅲ型噪爆,其辐射机制可能归因于基波等离子体辐射。
A decimetric type Ⅳ burst associated with type Ⅲ burst groups and type Ⅰ noise storm was observed with the solar radio spectrometers (1.0～2.0GHz and 2.6～3.8GHz) at National Astronomical Observatories of China (NAOC) on September 23,1998.The type Ⅰ noise storm occurred in the decaying phase of the type Ⅳ burst is emphatically discussed.This noise storm consists of many type Ⅰ bursts.The duration of each type Ⅰ burst is of the order of 100-300 ms.The total duration is greater than 11 minutes.Moreover,this noise storm also consists of other fast fine structures,such as single spike or type Ⅲ bursts,spike group,and the pair of type Ⅲ bursts.The durations of these fine structures are in the range about 100-300 ms.Probably,there are some fine structures with durations less than 100 ms,but they are not found because of the limitation of the time resolution of the instrument.The circular polarization degree of the type Ⅰ noise storm emission is greater than that of the type Ⅳ continuum emission,and with an average value of 64%.The polarization degree of the type Ⅲ bursts are almost 100%,which are week intensity bursts with strong polarization.The type Ⅰ noise storm may be attributed to the fundamental plasma radiation similar to the high polarized type Ⅲ noise storm.Because the traditional type Ⅰ noise storm is occurred in the range from meter to decameter wavelengths,the decimetric type Ⅰ noise storm may be the extension of the metric one,or may be the behavior of the transition region.Because the type Ⅰ and Ⅲ bursts are occurred simultaneously,this possibly means that they are attributed to the same electron beams.
出处
《云南天文台台刊》
CSCD
北大核心
2003年第2期36-42,共7页
Publications of the Yunnan Observatoty
