论文标题
在星际灭绝曲线II中的可见连续体和频带上
On the visible continuum and bands in the interstellar extinction curve II
论文作者
论文摘要
化学结构的任何失真都会导致新特征出现在结构的吸收光谱中，尤其是在可见的和近乎紫外线附近（请参阅纸张I）。使用分子轨道理论的化学建模表明，该范围内弱新频段的积累产生的连续体正确地模拟了实验室中在纯合成硅酸盐的实验室中测量的连续体，在透明频谱范围内以及在同一范围内的跨层次灭绝曲线中。 本文更详细地探讨了由于失真而从连续体中出现的强大离散带。发现不同类型的结构（线性或紧凑，碳或硅含）在不同的波长下具有有限数量的强，特征性的频带。 失真只是``缺陷''的一个实例，它丰富了vis/uv吸收光谱；其他的是：空缺和空隙，替代，杂质，杂质，悬挂式债券的倾向。这些积累导致``无定形''结构状态。下面描述了在实验室中分析并在理论上进行模拟的几个已知无定形材料的例子，这些例子已在下面进行了分析，从而扩大了这项工作的范围。最后一部分列出了使用或可能使用无定形模型的天体物理学领域。
Any distortion of a chemical structure causes new features to appear in the absorption spectrum of the structure, especially in the visible and near UV (see Paper I). Chemical modeling, using molecular orbital theory, showed that the continuum resulting from the accumulation of weak new bands in that range, correctly mimics the continuum measured in the laboratory on pure synthesized silicates, in the transparency spectral range, as well as in the InterStellar extinction curve in the same range. The present paper explores in more detail the strong discrete bands that emerge from the continuum due to distortion. It is found that different types of structure (linear or compact, carbon- or silicon-bearing) have each a limited number of strong, characteristic, bands at different wavelengths. Distortion is only one instance of ``defects'' that enrich the vis/UV absorption spectrum; others are: vacancies and voids, substitutions, inclusions in interstices, impurities, dangling bonds. The accumulation of these result in an ``amorphous'' structural state. Several examples of known amorphous materials, both carbon- and silicon-bearing, that have been analyzed in the laboratory, and simulated theoretically, are described below, thus extending the scope of this work. A final section lists several fields of astrophysics that have used, or may use, amorphous models of dust.
