Mercury: Thermal Modeling and Mid-infrared (5–12 μm) Observations☆
Mercury: Thermal Modeling and Mid-infrared (5–12 μm) Observations☆
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水星：热模拟和中红外（5–12 μm）观测☆
DOI：
10.1006/icar.1998.6012
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发表时间：
1998
期刊：
影响因子：
3.2
通讯作者：
D. Wooden
中科院分区：
文献类型：
--
作者：
J. Emery;A. Sprague;F. Witteborn;J. Colwell;R. Kozlowski;D. Wooden
摘要：我们提出并使用了一个新的粗糙表面热模型，以帮助分析5-12.5 μm范围内汞的新中红外光谱测量结果。该模型计算缓慢旋转的无空气物体的空间分辨热发射。水星的数据包含了水星在5-7.5 μm之间的第一次光谱测量，这是地面望远镜无法获得的区域，也是在柯伊伯机载天文台（KAO）上飞行时对水星的第一次观测。它们是用高效红外微弱目标光栅光谱仪（HIFOGS）获得的。我们的粗糙表面热模型最适合KAO数据，其Hapke θ为20°。在两个观测周期内均存在强烈的5 μm发射特征。我们认为，5 μm的过量可能是30至100 μm粒度的风化层材料近地表热梯度的结果，但不能完全排除我们的仪器或KAO上的望远镜造成的观测伪像。光谱中的其他特征与长石和长石表面组成一致。
Abstract We present and use a new rough-surface thermal model to aid in the analysis of new mid-infrared spectral measurements of Mercury from 5–12.5 μm. The model calculates spatially resolved thermal emission from slowly rotating, airless bodies. The Mercury data contain the first spectral measurements of Mercury between 5–7.5 μm, a region not accessible from ground-based telescopes, and are also the first observations of Mercury to be made while flying on the Kuiper Airborne Observatory (KAO). They were obtained with the High- efficiency Infrared Faint Object Grating Spectrometer (HIFOGS). Our rough surface thermal model which best fit the KAO data has a Hapke θ of 20°. A strong 5-μm emission feature was present during both observing periods. We suggest the 5-μm excess may be a result of near surface thermal gradients in regolith materials with a 30 to 100-μm grainsize, but cannot entirely rule out an observational artifact resulting from our instrumentation or the telescope on the KAO. Other features in the spectra are consistent with a feldspathic and feldspathoidal surface composition.