Spectral Irradiance Calibration in the Infrared. VIII. 5-14 Micron Spectroscopy of the Asteroids Ceres, Vesta, and Pallas
Spectral Irradiance Calibration in the Infrared. VIII. 5-14 Micron Spectroscopy of the Asteroids Ceres, Vesta, and Pallas
复制标题
红外光谱辐照度校准。
DOI：
10.1086/300271
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
D. Wooden
中科院分区：
文献类型：
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作者：
M. Cohen;F. Witteborn;T. Roush;J. Bregman;D. Wooden
我们描述了我们通过将通过参考星绝对校准的小行星光谱与这些天体的“标准热模型”和“热物理模型”进行比较来在红外绝对校准计划中寻求“闭合”的努力。我们使用的连续5-14μm航空光谱提供了红外光谱能量分布的上升和峰值的完整采样，并约束了这些模型。这种模型目前支持红外空间观测台成像光偏振仪在远红外波长(最远300μm)的绝对校准，并有助于空间红外望远镜上的中红外光谱仪在6-12μm区域的绝对校准。与我们观测到的谷神星和灶神星光谱最匹配的是使用光束单位因子的标准热模型。我们还报告了CERES中存在的三个发射率特征，这可能会使传统的从同期地基N波段光度学外推到远红外的模型复杂化，例如，用于支持ISOPHOT校准的模型。虽然没有对导致这些特征的特定材料进行鉴定，但我们讨论了可能负有责任的矿物族。
We describe our efforts to seek "closure" in our infrared absolute calibration scheme by comparing spectra of asteroids, absolutely calibrated through reference stars, with "standard thermal models" and "thermophysical models" for these bodies. Our use of continuous 5–14 μm airborne spectra provides complete sampling of the rise to, and peak, of the infrared spectral energy distribution and constrains these models. Such models currently support the absolute calibration of the Infrared Space Observatory Imaging Photopolarimeter (ISOPHOT) at far-infrared wavelengths (as far as 300 μm) and contribute to that of the Mid-Infrared Spectrometer on the Infrared Telescope in Space in the 6–12 μm region. The best match to our observed spectra of Ceres and Vesta is a standard thermal model using a beaming factor of unity. We also report the presence of three emissivity features in Ceres that may complicate the traditional model extrapolation to the far-infrared from contemporaneous ground-based N-band photometry that is used to support calibration of, for example, ISOPHOT. While identification of specific materials that cause these features is not made, we discuss families of minerals that may be responsible.