| タイトル | High-Resolution IR Absorption Spectroscopy of Polycyclic Aromatic Hydrocarbons in the 3-micrometers Region: Role of Periphery |
| 本文（外部サイト） | http://hdl.handle.net/2060/20170001939 |
| 著者（英） | Oomens, Jos; Mackie, Cameron J.; Tielens, Alexander G. G. M.; Maltseva, Elena; Petrignani, Annemieke; Buma, Wybren Jan; Candian, Alessandra; Lee, Timothy J.; Huang, Xinchuan |
| 著者所属（英） | NASA Ames Research Center |
| 発行日 | 2017-01-01 |
| 言語 | eng |
| 内容記述 | In this work we report on high-resolution IR absorption studies that provide a detailed view on how the peripheral structure of irregular polycyclic aromatic hydrocarbons (PAHs) affects the shape and position of their 3-micrometers absorption band. To this purpose we present mass-selected, high-resolution absorption spectra of cold and isolated phenanthrene, pyrene, benz[a]antracene, chrysene, triphenylene, and perylene molecules in the 2950-3150 per cm range. The experimental spectra are compared with standard harmonic calculations, and anharmonic calculations using a modified version of the SPECTRO program that incorporates a Fermi resonance treatment utilizing intensity redistribution. We show that the 3-micrometers region is dominated by the effects of anharmonicity, resulting in many more bands than would have been expected in a purely harmonic approximation. Importantly, we find that anharmonic spectra as calculated by SPECTRO are in good agreement with the experimental spectra. Together with previously reported high-resolution spectra of linear acenes, the present spectra provide us with an extensive dataset of spectra of PAHs with a varying number of aromatic rings, with geometries that range from open to highly-condensed structures, and featuring CH groups in all possible edge configurations. We discuss the astrophysical implications of the comparison of these spectra on the interpretation of the appearance of the aromatic infrared 3-micrometers band, and on features such as the two-component emission character of this band and the 3-micrometers emission plateau. |
| NASA分類 | Inorganic, Organic and Physical Chemistry; Optics |
| レポートNO | ARC-E-DAA-TN37768 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
|
