First Detection of Solar Flare Emission in Mid-ultraviolet Balmer Continuum
First Detection of Solar Flare Emission in Mid-ultraviolet Balmer Continuum
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DOI：
10.3847/2041-8213/aaeace
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发表时间：
2018-10
期刊：
影响因子：
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通讯作者：
M. Dominique;A. Zhukov;P. Heinzel;I. Dammasch;L. Wauters;L. Dolla;S. Shestov;M. Kretzschmar;
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文献类型：
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作者：
M. Dominique;A. Zhukov;P. Heinzel;I. Dammasch;L. Wauters;L. Dolla;S. Shestov;M. Kretzschmar;
我们提出了第一次探测太阳耀斑发射在中紫外波长约2000毫米波的通道2的大产量辐射计（LYRA）上的PRoject机载自主2使命。耀斑（SOL 20170906）也在LYRA的通道1中观测到，中心位于1216 nm的H i Lyα线，在两个通道中都显示出明显的非热轮廓。通道2中的耀斑辐射与加热到10，000 K的光学薄色球板产生的氢巴耳末连续辐射一致。在通道1和通道2中同时观测，可以将线发射（主要来自Lyα线）与巴尔末连续谱发射分离。结合最近由界面区成像光谱仪探测到的近紫外线的巴耳末连续谱发射，LYRA观测加强了对宽带耀斑发射的解释，即起源于色球层的氢复合连续谱。
We present the first detection of solar flare emission at mid-ultraviolet wavelengths around 2000 Å by the channel 2 of the Large-Yield RAdiometer (LYRA) on board the PRoject for OnBoard Autonomy 2 mission. The flare (SOL20170906) was also observed in the channel 1 of LYRA centered at the H i Lyα line at 1216 Å, showing a clear non-thermal profile in both channels. The flare radiation in channel 2 is consistent with the hydrogen Balmer continuum emission produced by an optically thin chromospheric slab heated up to 10,000 K. Simultaneous observations in channels 1 and 2 allow the separation of the line emission (primarily from the Lyα line) from the Balmer continuum emission. Together with the recent detection of the Balmer continuum emission in the near-ultraviolet by the Interface Region Imaging Spectrometer, the LYRA observations strengthen the interpretation of broadband flare emission as the hydrogen recombination continua originating in the chromosphere.