A new method for determining temperature and emission measure during solar flares from light curves of soft X-ray line fluxes
A new method for determining temperature and emission measure during solar flares from light curves of soft X-ray line fluxes
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DOI：
10.1086/163264
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发表时间：
1985-06
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影响因子：
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通讯作者：
P. Bornmann
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文献类型：
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作者：
P. Bornmann
本文描述了在太阳耀斑衰变阶段观测到的软X射线线通量的一种新性质，以及一种利用这种性质来确定等离子体温度和辐射测量随时间变化的技术。本文分析的软X射线线通量是在1980年11月5日耀斑衰变阶段利用太阳极大任务(SMM)上的X射线多色仪(XRP)观测到的。Ne_(IX)，Mg_(XI)，Si_(13)，S(XV)，Ca_(XIX)，Fe_(XXV)的共振线，相互结合线和禁戒线，以及Lyman-.帽α.观察到了O-谱线和Fe-XIX谱线。观测到的谱线通量衰减的速率并不是恒定的。除了观察到的最高温度线以外，所有的温度线的速率都发生了突变，导致通量在耀斑衰变的后期以更快的速度下降。这些变化发生在较高温度下形成的谱线的较早时间。这一行为被认为是由于耀斑等离子体温度的下降跟踪了每条谱线发射率函数的上升和随后的下降。这一解释被用来对观察到的光曲线进行经验建模，并进一步估计衰变阶段作为时间函数的等离子体的温度和发射测量的变化。根据模型结果对各种等离子体参数进行了估计。
I describe a new property of soft X-ray line fluxes observed during the decay phase of solar flares and a technique for using this property to determine the plasma temperature and emission measure as functions of time. The soft X-ray line fluxes analyzed in this paper were observed during the decay phase of the 1980 November 5 flare by the X-Ray Polychromator (XRP) instrument on board the Solar Maximum Mission (SMM). The resonance, intercombination, and forbidden lines of Ne IX, Mg XI, Si XIII, S XV, Ca XIX, and Fe XXV, as well as the Lyman-..cap alpha.. line of O VIII and the resonance lines of Fe XIX, were observed. The rates at which the observed line fluxes decayed were not constant. For all but the highest temperature lines observed, the rate changed abruptly, causing the fluxes to fall at a more rapid rate later in the flare decay. These changes occurred at earlier times for lines formed at higher temperatures. This behavior is proposed to be due to the decreasing temperature of the flare plasma tracking the rise and subsequent fall of each line emissivity function. This explanation is used to empirically model the observed light curves and tomore » estimate the temperature and the change in emission measure of the plasma as a function of time during the decay phase. Estimates are made of various plasma parameters based on the model results.« less