Photometric and Thermal Cross-calibration of Solar EUV Instruments
Photometric and Thermal Cross-calibration of Solar EUV Instruments
复制标题
太阳能 EUV 仪器的光度和热交叉校准
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
C. Schrijver
中科院分区：
文献类型：
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作者：
P. Boerner;P. Testa;H. Warren;M. Weber;C. Schrijver
我们提出了校准测量和原子物理模型的准确性评估，用于计算SDO/AIA响应作为波长和温度的函数。通过将SDO/EVE和Hinode/EIS光谱数据与AIA有效面积函数进行卷积，并将预测结果与AIA观测结果进行比较，对波长响应进行了测试。对于大多数通道，在磁盘上总结的AIA强度与当前版本（V2） EVE数据得出的相应测量结果一致，在估计的25%校准误差之内。该协议表明AIA有效区域在时间上总体稳定。然而，AIA 304 Å通道，从2010年5月到2011年9月，当吞吐量明显达到最低水平时，确实显示出近3倍的退化。我们还在335 Å通带中发现了一些不一致，可能是由于EVE数据的高阶污染。AIA 193 Å通道的强度与EIS全CCD观测的相应测量值在不确定度范围内一致。通过对Procyon类太阳日冕和EVE光谱的高分辨率x射线光谱的分析，我们可以研究CHIANTI数据库在AIA短波段的准确性和完整性。我们发现，在94 Å通道中，由于大量缺失谱线，光谱模型明显低估了等离子体发射。通过对大量EVE光谱进行差分发射测量（DEM）反演，并调整AIA响应函数，使全盘DEM预测的计数率与观测值相匹配，对AIA温度响应进行了经验校正。
We present an assessment of the accuracy of the calibration measurements and atomic physics models that go into calculating the SDO/AIA response as a function of wavelength and temperature. The wavelength response is tested by convolving SDO/EVE and Hinode/EIS spectral data with the AIA effective area functions and by comparing the predictions with AIA observations. For most channels, the AIA intensities summed over the disk agree with the corresponding measurements derived from the current version (V2) of the EVE data to within the estimated 25 % calibration error. This agreement indicates that the AIA effective areas are generally stable in time. The AIA 304 Å channel, however, does show degradation by a factor of almost 3 from May 2010 through September 2011, when the throughput apparently reached a minimum. We also found some inconsistencies in the 335 Å passband, possibly due to higher-order contamination of the EVE data. The intensities in the AIA 193 Å channel agree to within the uncertainties with the corresponding measurements from EIS full CCD observations. Analysis of high-resolution X-ray spectra of the solar-like corona of Procyon and of EVE spectra allowed us to investigate the accuracy and completeness of the CHIANTI database in the AIA shorter wavelength passbands. We found that in the 94 Å channel, the spectral model significantly underestimates the plasma emission owing to a multitude of missing lines. We derived an empirical correction for the AIA temperature responses by performing differential emission measure (DEM) inversion on a broad set of EVE spectra and adjusting the AIA response functions so that the count rates predicted by the full-disk DEMs match the observations.