DECIMETRIC TYPE III BURSTS: GENERATION AND PROPAGATION
文献类型：期刊论文
| 作者 | Li, B.1; Cairns, Iver H.1; Yan, Y. H.2; Robinson, P. A.1 |
| 刊名 | ASTROPHYSICAL JOURNAL LETTERS
 |
| 出版日期 | 2011-09-01 |
| 卷号 | 738期号:1 |
| 关键词 | methods: numerical Sun: corona Sun: radio radiation |
| 英文摘要 | Simulations are presented for decimetric type III radio bursts at 2f(p), where f(p) is the local electron plasma frequency. The simulations show that 2f(p) radiation can be observed at Earth in two scenarios for the radiation's generation and propagation. In Scenario A, radiation is produced and propagates in warm plasmas in the lower corona that are caused by previous magnetic reconnection outflows and/or chromospheric evaporation. In Scenario B radiation is generated in normal plasmas, then due to its natural directivity pattern and refraction, radiation partly propagates into nearby regions, which are hot because of previous reconnection/evaporation. The profiles of plasma density n(e)(r) and electron temperature T-e(r) in the lower corona (r - R-circle dot less than or similar to 100 Mm) are found to be crucial to whether radiation can be produced and escape at observable levels against the effects of free-free absorption, where r is the heliocentric distance. Significantly, the observed wide ranges of radiation properties (e. g., drift rates) require n(e)(r) with a large range of scale heights h(s), consistent nonetheless for Scenario B with short observed EUV loops. This is relevant to problems with large h(s) inferred from tall EUV loops. The simulations suggest: (1) n(e)(r) with small h(s), such as n(e)(r) proportional to (r - R-circle dot)(-2.38) for flaring regions, are unexpectedly common deep in the corona. This result is consistent with recent work on n(e)(r) for r approximate to (1.05-2)R-circle dot extracted from observed metric type IIIs. (2) The dominance of reverse-slope bursts over normal bursts sometimes observed may originate from asymmetric reconnection/acceleration, which favors downgoing beams. |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000293961400009 |
| 源URL | [http://ir.bao.ac.cn/handle/114a11/7904]  |
| 专题 | 国家天文台_太阳物理研究部 |
| 作者单位 | 1.Univ Sydney, Sch Phys, Sydney, NSW 2006, Australia 2.Chinese Acad Sci, Key Lab Solar Act, Natl Astron Observ, Beijing, Peoples R China |
| 推荐引用方式 GB/T 7714 | Li, B.,Cairns, Iver H.,Yan, Y. H.,et al. DECIMETRIC TYPE III BURSTS: GENERATION AND PROPAGATION[J]. ASTROPHYSICAL JOURNAL LETTERS,2011,738(1). |
| APA | Li, B.,Cairns, Iver H.,Yan, Y. H.,&Robinson, P. A..(2011).DECIMETRIC TYPE III BURSTS: GENERATION AND PROPAGATION.ASTROPHYSICAL JOURNAL LETTERS,738(1). |
| MLA | Li, B.,et al."DECIMETRIC TYPE III BURSTS: GENERATION AND PROPAGATION".ASTROPHYSICAL JOURNAL LETTERS 738.1(2011). |
入库方式： OAI收割
来源：国家天文台
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