Decimetric spike bursts versus microwave continuum

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	Decimetric spike bursts versus microwave continuum
	Fleishman, GD ; Gary, DE ; Nita, GM
刊名	ASTROPHYSICAL JOURNAL
	2003-08-10
卷号	593 期号:1 页码:571-580
关键词	acceleration of particles Sun : flares Sun : particle emission Sun : radio radiation
英文摘要	We analyze properties of decimetric spike bursts occurring simultaneously with microwave gyrosynchrotron continuum bursts. We found that all of the accompanying microwave bursts were highly polarized in the optically thin range. The sense of polarization of the spike clusters is typically the same as that of the optically thin gyrosynchrotron emission, implying preferential extraordinary wave-mode spike polarization. Optically thick spectral indices of the continuum in spike-producing events were not observed to be larger than 2.5, suggesting low or absent Razin suppression. This implies that the plasma frequency-to-gyrofrequency ratio is systematically lower in the spike-producing bursts than in other bursts. The spike cluster flux density is found to be tightly correlated with the high-frequency spectral index of the microwave continuum for each event, while the flux-to-flux correlation may not be present. We discovered strong evidence that the trapped fast electrons producing the microwave gyrosynchrotron continuum have an anisotropic pitch-angle distribution of the loss cone type in the spike-producing bursts. The spike clusters are mainly generated when the trapped electrons have the hardest and the most anisotropic distributions. The new properties are discussed against the currently available ideas about emission processes and models for spike generation. We conclude that the findings strongly support the electron cyclotron maser mechanism of spike emission, with characteristics agreeing with expectations from the local-trap model.
WOS标题词	Science & Technology ; Physical Sciences
类目[WOS]	Astronomy & Astrophysics
研究领域[WOS]	Astronomy & Astrophysics
关键词[WOS]	ELECTRON-CYCLOTRON MASER ; SOLAR RADIO SPIKES ; BAND DM-SPIKES ; X-RAY-EMISSION ; GYROSYNCHROTRON EMISSION ; ENERGETIC ELECTRONS ; NONLINEAR TREATMENT ; MILLISECOND SPIKES ; MAGNETIC-FIELD ; FINE-STRUCTURE
收录类别	SCI
语种	英语
WOS记录号	WOS:000184585600045
内容类型	期刊论文
源URL	[http://libir.pmo.ac.cn/handle/332002/15829]
专题	紫金山天文台_暗物质和空间天文实验室
作者单位	1.Acad Sinica, Purple Mt Observ, Natl Astron Observ, Nanjing 210008, Peoples R China 2.New Jersey Inst Technol, Newark, NJ 07102 USA 3.AF Ioffe Inst Phys & Technol, St Petersburg 194021, Russia
推荐引用方式 GB/T 7714	Fleishman, GD,Gary, DE,Nita, GM. Decimetric spike bursts versus microwave continuum[J]. ASTROPHYSICAL JOURNAL,2003,593(1):571-580.
APA	Fleishman, GD,Gary, DE,&Nita, GM.(2003).Decimetric spike bursts versus microwave continuum.ASTROPHYSICAL JOURNAL,593(1),571-580.
MLA	Fleishman, GD,et al."Decimetric spike bursts versus microwave continuum".ASTROPHYSICAL JOURNAL 593.1(2003):571-580.