Astronomy and Astrophysics – Astrophysics
Scientific paper
Mar 1985
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1985apj...290l..25a&link_type=abstract
Astrophysical Journal, Part 2 - Letters to the Editor (ISSN 0004-637X), vol. 290, March 1, 1985, p. L25-L28.
Astronomy and Astrophysics
Astrophysics
623
Aromatic Compounds, Hydrocarbons, Infrared Spectra, Interstellar Matter, Milky Way Galaxy, Exhaust Emission, Fluorescence, Molecular Excitation, Particulates, Raman Spectra, Spectral Bands, Spectral Line Width, Vibrational Spectra
Scientific paper
The unidentified infrared emission features (UIR bands) are attributed to a collection of partially hydrogenated, positively charged polycyclic aromatic hydrocarbons (PAHs). This assignment is based on a spectroscopic analysis of the UIR bands. Comparison of the observed interstellar 6.2 and 7.7-micron bands with the laboratory measured Raman spectrum of a collection of carbon-based particulates (auto exhaust) shows a very good agreement, supporting this identification. The infrared emission is due to relaxation from highly vibrationally and electronically excited states. The excitation is probably caused by UV photon absorption. The infrared fluorescence of one particular, highly vibrationally excited PAH (chrysene) is modeled. In this analysis the species is treated as a molecule rather than bulk material and the non-thermodynamic equilibrium nature of the emission is fully taken into account. From a comparison of the observed ratio of the 3.3 to 11.3-micron UIR bands with the model calculations, the average number of carbon atoms per molecule is estimated to be about 20. The abundance of interstellar PAHs is calculated to be about 2 x 10 to the -7th with respect to hydrogen.
Allamandola Louis J.
Barker Richard J.
Tielens Alexander G. G. M.
No associations
LandOfFree
Polycyclic aromatic hydrocarbons and the unidentified infrared emission bands - Auto exhaust along the Milky Way does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Polycyclic aromatic hydrocarbons and the unidentified infrared emission bands - Auto exhaust along the Milky Way, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Polycyclic aromatic hydrocarbons and the unidentified infrared emission bands - Auto exhaust along the Milky Way will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-819200