Li Chun-sheng, Zheng Xing-wu, Jiang Shu-ying, Yao Jin-xing, Zhou Ai-hua
{"title":"Mechanism for producing the U-shaped spectrum of the type-IV solar radio bursts","authors":"Li Chun-sheng, Zheng Xing-wu, Jiang Shu-ying, Yao Jin-xing, Zhou Ai-hua","doi":"10.1016/0146-6364(80)90046-8","DOIUrl":null,"url":null,"abstract":"<div><p>A mechanism is proposed to account for the U-shaped spectrum of the type IV solar radio burst during the explosive phase of proton flare. The U-shaped spectrum consists of two parts, namely the part of type IV<sub><em>μ</em></sub> burst and that the type IV<sub><em>dm</em></sub> burst. Each of them is believed to be produced by gyrosynchroton radiation of nonthermal electrons (100keV ≤ <em>ϵ</em> ≤ 2MeV) accelerated simultaneously with protons in explosive phase and gyroresonance absorption of thermal electrons.</p><p>Numerical calculations are presented for the flux densities of type IV<sub><em>μ</em></sub> burst and type IV<sub><em>dm</em></sub> during 7 August 1972 event, assuming the volume of these burst sources being cylinders. It is shown that the results of numerical calculations are consistent with that of observations.</p><p>The reversal of polarized waves sense from type IV<sub><em>μ</em></sub> burst source into type IV<sub><em>dm</em></sub> sources is explained by the fact that the direction of the magnetic field line in one source is anti-parallel to that in the other.</p><p>Besides, we also discuss the relation between the U-shaped spectrum of type IV radio burst and the occurrence of proton event.</p></div>","PeriodicalId":100241,"journal":{"name":"Chinese Astronomy","volume":"4 2","pages":"Pages 155-162"},"PeriodicalIF":0.0000,"publicationDate":"1980-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0146-6364(80)90046-8","citationCount":"5","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chinese Astronomy","FirstCategoryId":"1085","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/0146636480900468","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 5
Abstract
A mechanism is proposed to account for the U-shaped spectrum of the type IV solar radio burst during the explosive phase of proton flare. The U-shaped spectrum consists of two parts, namely the part of type IVμ burst and that the type IVdm burst. Each of them is believed to be produced by gyrosynchroton radiation of nonthermal electrons (100keV ≤ ϵ ≤ 2MeV) accelerated simultaneously with protons in explosive phase and gyroresonance absorption of thermal electrons.
Numerical calculations are presented for the flux densities of type IVμ burst and type IVdm during 7 August 1972 event, assuming the volume of these burst sources being cylinders. It is shown that the results of numerical calculations are consistent with that of observations.
The reversal of polarized waves sense from type IVμ burst source into type IVdm sources is explained by the fact that the direction of the magnetic field line in one source is anti-parallel to that in the other.
Besides, we also discuss the relation between the U-shaped spectrum of type IV radio burst and the occurrence of proton event.