The 11.2 $\mu$m emission of PAHs in astrophysical objects
Abstract
The 11.2 m emission band belongs to the family of the `Unidentified' Infrared (UIR) emission bands seen in many astronomical environments. In this work we present a theoretical interpretation of the band characteristics and profile variation for a number of astrophysical sources in which the carriers are subject to a range of physical conditions. The results of Density Functional Theory (DFT) calculations for the solo out-of-plane (OOP) vibrational bending modes of large polycyclic aromatic hydrocarbon (PAH) molecules are used as input for a detailed emission model which includes the temperature and mass dependence of PAH band wavelength, and a PAH mass distribution that varies with object. Comparison of the model with astronomical spectra indicates that the 11.2 m band asymmetry and profile variation can be explained principally in terms of the mass distribution of neutral PAHs with a small contribution from anharmonic effects.
Keywords
Cite
@article{arxiv.1501.06811,
title = {The 11.2 $\mu$m emission of PAHs in astrophysical objects},
author = {A. Candian and P. J. Sarre},
journal= {arXiv preprint arXiv:1501.06811},
year = {2015}
}
Comments
13 pages, 10 figures, 3 table. Accepted for publication in MNRAS