Abstract

The Unidentified Infrared bands (UIBs or UIRs) known also as Aromatic Infrared Bands (AIBs) represent a series of discrete infrared emission bands detected in numerous and very different astrophysical objects. The carriers of these infrared bands have not yet unambiguously identified. The MAONs model proposes that the carriers of the UIBs could be described by an “average” chemical structure consisting of mixed aromatic-aliphatic organic nanoparticles (MAONs) and containing also heteroatoms such as N, S and O. Asphaltenes are matching quite well the MAONs model and in this work a series of selected asphaltenes from petroleum were carbonized at 700 °C in sealed crucible under inert atmosphere leading to a carbon coke. Both the starting asphaltenes and the result of their carbonization were studied with FT-IR spectroscopy. It is shown that the asphaltenes and the resulting coke can be considered excellent model compounds for the UIBs’ carriers and their evolution because of thermal and radiation processing of the latter in the harsh space environment.

摘要

未知红外波段（UIB 或 UIR）也称为芳香红外波段 (AIB)，代表在众多且非常不同的天体物理物体中检测到的一系列离散红外发射波段。这些红外波段的载波尚未明确识别。MAONs 模型提出，UIB 的载体可以用“平均”化学结构来描述，该化学结构由混合的芳族-脂肪族有机纳米粒子 (MAON) 组成，还包含 N、S 和 O 等杂原子。沥青质与 MAON 非常匹配模型和在这项工作中，一系列从石油中选择的沥青质在惰性气氛下在密封坩埚中于 700°C 碳化，产生碳焦。使用 FT-IR 光谱研究了起始沥青质及其碳化结果。