Research Progress of Electron Cyclotron Maser Emission on Solar Physics

	Research Progress of Electron Cyclotron Maser Emission on Solar Physics
	Tang Jianfei; Wu Dejin; Zhao Guoqing; Chen Ling
刊名	Progress in Astronomy
	2017
卷号	35 期号:2 页码:149-174
英文摘要	Electron-cyclotron maser (ECM) emission is a well-known radiation emission mechanism in astrophysics. It has been extensively applied to various nonthermal coherent radio emission, especially to the short-timescale coherent radio bursts. Excitation of electron cyclotron maser radiation requires two basic conditions. One is the inversion distribution of the energetic electrons in the direction perpendicular to the ambient magnetic field. The other is the escape difficulty that requires the local electron cyclotron frequency over the plasma frequency. These two conditions are hardly satisfied in the corona under the conventional solar atmosphere models, which limit the application of ECM emission mechanism to solar radio astronomy. In general, flare associated energetic electrons are accelerated initially mainly along the magnetic field, it means that these energetic electrons do not have enough free energy to drive ECM emission. After the energetic electrons leave the acceleration site and propagate in the solar atmosphere, the energy of the energetic electrons in the parallel orientation can be transfer to the perpendicular orientation, and form an anisotropic distribution due to the interaction of energetic electrons with magnetic field and plasma waves. For the escape difficulty, a density depletion duct in the corona is necessary and may be rational as optical observations show fibrous density structures exist commonly in the corona. This paper presents a systematic review on the recent development of ECM emission mechanism, especially on the new models which may overcome the above difficulties and can be applied in several kinds of solar radio bursts, such as type I bursts, type II bursts, and type V bursts. Some perspectives on the study of ECM mechanism and solar radio emission processes are also presented.
语种	英语
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/17393]
专题	中国科学院紫金山天文台
推荐引用方式 GB/T 7714	Tang Jianfei,Wu Dejin,Zhao Guoqing,et al. Research Progress of Electron Cyclotron Maser Emission on Solar Physics[J]. Progress in Astronomy,2017,35(2):149-174.
APA	Tang Jianfei,Wu Dejin,Zhao Guoqing,&Chen Ling.(2017).Research Progress of Electron Cyclotron Maser Emission on Solar Physics.Progress in Astronomy,35(2),149-174.
MLA	Tang Jianfei,et al."Research Progress of Electron Cyclotron Maser Emission on Solar Physics".Progress in Astronomy 35.2(2017):149-174.