Linear spectropolarimetry: a new diagnostic tool for the classification and characterization of asteroids
Linear spectropolarimetry: a new diagnostic tool for the classification and characterization of asteroids
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DOI：
10.1093/mnrasl/slu154
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发表时间：
2014-09
影响因子：
4.8
通讯作者：
S. Bagnulo;A. Cellino;M. Sterzik
中科院分区：
文献类型：
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作者：
S. Bagnulo;A. Cellino;M. Sterzik
我们探讨使用光谱偏振作为遥感工具，除了传统的反射率测量小行星。特别是，我们感兴趣的线性偏振的波长依赖性的变化和表面的性质，包括反射率和组合物之间的可能关系。我们已经获得了12个不同的小行星和分类类和两个小区域在月球边缘的光学光谱偏振测量。我们发现，具有略微不同的相对反射光谱（在光学上）的物体可能具有完全不同的偏振光谱。这表明分光偏振法可用于改进小行星的分类。我们还发现，在某些情况下，Umov定律可能会被违反，即与基本物理考虑的预期相反，线极化率和反射率可能正相关。在协议与以前的几个研究的基础上多色宽带偏振，我们发现，线性偏振与波长和相位角的变化是相关的，与物体的颜色和分类类。最后，我们偶然发现富含尖晶石的小行星（599）Luisa非常接近Watsonia家族，是罕见的野蛮小行星类别的成员。我们建议，未来的小行星的表面结构的建模尝试，应旨在解释反射和偏振光谱。
We explore the use of spectro-polarimetry as a remote sensing tool for asteroids in addition to traditional reflectance measurements. In particular we are interested in possible relationships between the wavelength-dependent variation of linear polarization and the properties of the surfaces, including albedo and composition. We have obtained optical spectro-polarimetric measurements of a dozen asteroids of different albedo and taxonomic classes and of two small regions at the limb of the Moon. We found that objects with marginally different relative reflectance spectra (in the optical) may have totally different polarization spectra. This suggests that spectropolarimetry may be used to refine the classification of asteroids. We also found that in some cases the Umov law may be violated, that is, in contrast to what is expected from basic physical considerations, the fractio no f linear polarization and the ref lectance may be positively correlated. In agreement with a few previous studies based on multicolour broadband polarimetry, we found that the variation of linear polarization with wavelength and with phase-angle is correlated with the albedo and taxonomic class of the objects. Finally, we have serendipitously discovered that spinel-rich asteroid (599)Luisa, located very close to the Watsonia family, is a member of the rare class of Barbarian asteroids. We suggest that future modelling attempts of the surface structure of asteroids should be aimed at explaining both reflectance and polarization spectra.