Infrared Spectra of Comets as a Barometer for Their Evolution

我们发现，彗星尘埃聚集体的分形维数决定了彗星彗星尘埃红外光谱中橄榄石特征峰的强度，而尘埃聚集体中有机耐火材料的体积分数和碳化程度对确定峰波长起着重要作用。此外，分形维数的增加和有机耐火材料的碳化都与彗星表面尘埃地幔的形成有关。因此，彗星彗星的红外光谱可以作为彗星演化和彗星颗粒性质变化的晴雨表。由于彗星尘埃的处理是随着母体彗星的轨道进行的，我们预计，对红外数据的彻底分析将揭示橄榄石的光谱特征与彗星轨道半长轴之间的相关性。

We have found that the fractal dimension of aggregated dust particles in comets determines the strength of peaks characteristic of olivine detected in the infrared spectra of dust in cometary comae, while the volume fraction and carbonization of organic refractory material in the dust aggregates play an important role in the determination of the peak wavelengths. Furthermore, both an increase in the fractal dimension and the carbonization of organic refractory material are associated with the formation of a dust mantle on the surface of a comet. Therefore, the infrared spectra of cometary comae can be regarded as a barometer of the evolution of comets as well as the alteration of comet grain properties. Since the processing of comet dust proceeds with the orbit of the parent-body comet, we expect that a thorough analysis of infrared data will reveal a correlation between the spectral features characteristic of olivine and the orbital semi-major axes of comets.