SOLAR FLARE CHROMOSPHERIC LINE EMISSION: COMPARISON BETWEEN IBIS HIGH-RESOLUTION OBSERVATIONS AND RADIATIVE HYDRODYNAMIC SIMULATIONS
SOLAR FLARE CHROMOSPHERIC LINE EMISSION: COMPARISON BETWEEN IBIS HIGH-RESOLUTION OBSERVATIONS AND RADIATIVE HYDRODYNAMIC SIMULATIONS
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DOI：
10.1088/0004-637x/804/1/56
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发表时间：
2014-12
期刊：
影响因子：
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通讯作者：
F. R. D. Costa;L. Kleint;V. Petrosian;A. S. Dalda;Wei Liu
中科院分区：
文献类型：
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作者：
F. R. D. Costa;L. Kleint;V. Petrosian;A. S. Dalda;Wei Liu
太阳耀斑涉及脉冲能量释放，这导致在宽光谱范围和宽高度范围内的辐射增强。特别是，从色球层的线发射可以提供等离子体加热过程的关键诊断。因此，高分辨率光谱观测和先进的数值模拟结果之间的直接比较可能是非常有价值的，但尚未尝试。在本文中，我们提出了这样一个自洽调查的M3.0耀斑观测的邓恩太阳望远镜的干涉二维光谱仪（IBIS）在2011年9月24日，我们使用辐射流体动力学代码RADYN建模。我们用IBIS在Hα 6563 <$A和Ca ii 8542 <$A中获得了耀斑区的图像和光谱，用RHESSI在X射线中获得了耀斑区的图像和光谱。后者的观测被用来推断非热电子的人口，这是通过RADYN模拟大气响应电子碰撞加热。然后，我们合成了光谱线，并将它们的形状和强度与IBIS观察到的进行了比较，发现基本一致。特别是，合成的Ca ii 8542 α剖面与观测剖面吻合良好，而合成的Hα剖面在岩心中比观测的要弱。这表明Hα发射比Ca ii 8542 γ发射对非热电子通量更敏感。我们建议有必要改进能量输入和其他过程来解决这种差异。
Solar flares involve impulsive energy release, which results in enhanced radiation over a broad spectral range and a wide range of heights. In particular, line emission from the chromosphere can provide critical diagnostics of plasma heating processes. Thus, a direct comparison between high-resolution spectroscopic observations and advanced numerical modeling results could be extremely valuable, but has not yet been attempted. In this paper, we present such a self-consistent investigation of an M3.0 flare observed by the Dunn Solar Telescope’s Interferometric Bi-dimensional Spectrometer (IBIS) on 2011 September 24 which we have modeled using the radiative hydrodynamic code RADYN. We obtained images and spectra of the flaring region with IBIS in Hα 6563 Å and Ca ii 8542 Å, and with RHESSI in X-rays. The latter observations were used to infer the non-thermal electron population, which was passed to RADYN to simulate the atmospheric response to electron collisional heating. We then synthesized spectral lines and compared their shapes and intensities to those observed by IBIS and found a general agreement. In particular, the synthetic Ca ii 8542 Å profile fits well to the observed profile, while the synthetic Hα profile is fainter in the core than for the observation. This indicates that Hα emission is more responsive to the non-thermal electron flux than the Ca ii 8542 Å emission. We suggest that it is necessary to refine the energy input and other processes to resolve this discrepancy.