中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
RELATIONSHIP BETWEEN HARD AND SOFT X-RAY EMISSION COMPONENTS OF A SOLAR FLARE

文献类型:期刊论文

作者Guo, Jingnan1,2,3; Liu, Siming1,3; Fletcher, Lyndsay1; Kontar, Eduard P.1
刊名ASTROPHYSICAL JOURNAL
出版日期2011-02-10
卷号728期号:1页码:4(12pp)
关键词radiation mechanisms: non-thermal radiation mechanisms: thermal Sun: flares Sun: X-rays, gamma rays
ISSN号0004-637X
英文摘要X-ray observations of solar flares routinely reveal an impulsive high-energy and a gradual low-energy emission component, whose relationship is one of the key issues of solar flare study. The gradual and impulsive emission components are believed to be associated with, respectively, the thermal and nonthermal components identified in spectral fitting. In this paper, a prominent similar to 50 s hard X-ray (HXR) pulse of a simple GOES class C7.5 flare on 2002 February 20 is used to study the association between high-energy, non-thermal, and impulsive evolution, and low-energy, thermal, and gradual evolution. We use regularized methods to obtain time derivatives of photon fluxes to quantify the time evolution as a function of photon energy, obtaining a break energy between impulsive and gradual behavior. These break energies are consistent with a constant value of similar to 11 keV in agreement with those found spectroscopically between thermal and non-thermal components, but the relative errors of the former are greater than 15% and much greater than the few percent errors found from the spectral fitting. These errors only weakly depend on assuming an underlying spectral model for the photons, pointing to the current data being inadequate to reduce the uncertainties rather than there being a problem associated with an assumed model. The time derivative method is used to test for the presence of a "pivot energy" in this flare. Although these pivot energies are marginally consistent with a constant value of similar to 9 keV, its values in the HXR rise phase appear to be lower than those in the decay phase. Assuming that electrons producing the high-energy component have a power-law distribution and are accelerated from relatively hot regions of a background plasma responsible for the observed thermal component, a low limit is obtained for the low-energy cutoff. This limit is always lower than the break and pivot energies and is located in the tail of the Maxwellian distribution of the thermal component.
WOS标题词Science & Technology ; Physical Sciences
学科主题Astronomy & Astrophysics
类目[WOS]Astronomy & Astrophysics
研究领域[WOS]Astronomy & Astrophysics
关键词[WOS]ENERGY-RELEASE EVENTS ; OF-FLIGHT DISTANCES ; PARTICLE-ACCELERATION ; SPECTRAL EVOLUTION ; ELECTRON ACCELERATION ; RHESSI ; EVAPORATION ; PARTITION ; TRANSPORT ; CUTOFFS
收录类别SCI
语种英语
WOS记录号WOS:000286655500004
公开日期2012-08-07
源URL[http://libir.pmo.ac.cn/handle/332002/4485]  
专题紫金山天文台_太阳高能及相关物理过程研究团组
作者单位1.Univ Glasgow, Sch Phys & Astron, SUPA, Glasgow G12 8QQ, Lanark, Scotland
2.Max Planck Inst Solar Syst Res, D-37191 Katlenburg Lindau, Germany
3.Purple Mt Observ, Nanjing 210008, Peoples R China
推荐引用方式
GB/T 7714
Guo, Jingnan,Liu, Siming,Fletcher, Lyndsay,et al. RELATIONSHIP BETWEEN HARD AND SOFT X-RAY EMISSION COMPONENTS OF A SOLAR FLARE[J]. ASTROPHYSICAL JOURNAL,2011,728(1):4(12pp).
APA Guo, Jingnan,Liu, Siming,Fletcher, Lyndsay,&Kontar, Eduard P..(2011).RELATIONSHIP BETWEEN HARD AND SOFT X-RAY EMISSION COMPONENTS OF A SOLAR FLARE.ASTROPHYSICAL JOURNAL,728(1),4(12pp).
MLA Guo, Jingnan,et al."RELATIONSHIP BETWEEN HARD AND SOFT X-RAY EMISSION COMPONENTS OF A SOLAR FLARE".ASTROPHYSICAL JOURNAL 728.1(2011):4(12pp).

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来源:紫金山天文台

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