论文标题
JWST Miri/MRS机上绝对通量校准和未解决来源的量身定制的附带校正
JWST MIRI/MRS in-flight absolute flux calibration and tailored fringe correction for unresolved sources
论文作者
论文摘要
MRS是JWST/MIRI的四个观察模式之一。使用未解决（点）源的JWST机上数据，我们可以从原始数据开始得出MRS绝对光谱响应函数（ASRF）。光谱条纹在MRS ASRF的推导和解释中起关键作用。在本文中，我们提出了一种校准数据的替代方法。首先，我们旨在得出一个条纹校正，该条纹校正解释了点扩散函数的流条纹对图中瞳孔照明和检测器像素采样的依赖性。其次，我们旨在使用在MRS的整个5至28 $μm波长范围内观察到的绝对通量校准器来得出MRS ASRF。第三，我们旨在将新的ASRF应用于g矮人的频谱，并与JWST/MIRI默认数据减少管道的输出进行比较。最后，我们研究了不同边缘校正对G矮人和K巨人分子特征的可检测性的影响。绝对通量校准器HD 163466（A-Star）用于在MRS的每个默认抖动位置得出量身定制的点源条纹平面。 HD 163466的边缘校正点源积分频谱用于使用恒星连续体的理论模型来得出MRS ASRF。运行互相关以量化G矮人中K巨人和CO中CO，SIO和OH检测的不确定性，以进行不同的条纹校正。发现点源量的条纹校正和ASRF的性能与当前校正相同，使边缘与次级水平形成鲜明对比，同时缓解了实际分子特征的改变。可以将相同的量身定制溶液应用于其他未解决的MRS未解决的靶标。在MRS中，指向重复性问题限制了量身定制的条纹平面的有效性在短波长下。
The MRS is one of the four observing modes of JWST/MIRI. Using JWST in-flight data of unresolved (point) sources, we can derive the MRS absolute spectral response function (ASRF) starting from raw data. Spectral fringing plays a critical role in the derivation and interpretation of the MRS ASRF. In this paper, we present an alternative way to calibrate the data. Firstly, we aim to derive a fringe correction that accounts for the dependence of the fringe properties on the MIRI pupil illumination and detector pixel sampling of the point spread function. Secondly, we aim to derive the MRS ASRF using an absolute flux calibrator observed across the full 5 to 28 $μ$m wavelength range of the MRS. Thirdly, we aim to apply the new ASRF to the spectrum of a G dwarf and compare with the output of the JWST/MIRI default data reduction pipeline. Finally, we examine the impact of the different fringe corrections on the detectability of molecular features in the G dwarf and K giant. The absolute flux calibrator HD 163466 (A-star) is used to derive tailored point source fringe flats at each of the default dither locations of the MRS. The fringe-corrected point source integrated spectrum of HD 163466 is used to derive the MRS ASRF using a theoretical model for the stellar continuum. A cross-correlation is run to quantify the uncertainty on the detection of CO, SiO, and OH in the K giant and CO in the G dwarf for different fringe corrections. The point-source-tailored fringe correction and ASRF are found to perform at the same level as the current corrections, beating down the fringe contrast to the sub-percent level, whilst mitigating the alteration of real molecular features. The same tailored solutions can be applied to other MRS unresolved targets. A pointing repeatability issue in the MRS limits the effectiveness of the tailored fringe flats is at short wavelengths.
