Simulated infrared emission spectra of highly excited polyatomic molecules: A detailed model of the PAH-UIR hypothesis

被引：116

作者：

Cook, DJ ^{[1
]}

Saykally, RJ ^{[1
]}

机构：

[1] Univ Calif Berkeley, Dept Chem, Berkeley, CA 94720 USA

来源：

ASTROPHYSICAL JOURNAL | 1998年 / 493卷 / 02期

关键词：

infrared; ISM; lines and bands; molecules; molecular data; molecular processes; planetary nebulae; general; radiation mechanisms; nonthermal;

D O I：

10.1086/305156

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

A detailed description of the polycyclic aromatic hydrocarbon (PAH)/unidentified infrared band (UIR) mechanism is presented in which experimental spectral bandshape functions are used to simulate IR emission spectra for individual molecules. These spectra are additively superimposed to produce a conglomerate spectrum representative of a family of PAH molecules. Ab initio vibrational frequencies and intensities for nine PAHs (neutral and cationic) as large as ovalene are used in conjunction with measured bandshape and temperature-dependent redshift data to simulate the UIR bands. The calculated spectra of cations provide a closer match to the UIRs than do those of the neutrals. However, the PAH cations used in the simulations fail to reproduce the details of the UIR emission spectra. The discrepancies are potentially alleviated if both larger PAHs and a greater number of PAHs were included in the simulation.

引用

页码：793 / 802

页数：10

共 36 条

[31] INFRARED FREQUENCIES AND INTENSITIES FOR ASTROPHYSICALLY IMPORTANT POLYCYCLIC AROMATIC HYDROCARBON CATIONS [J].