Electronic spectroscopy of medium-sized polycyclic aromatic hydrocarbons: Implications for the carriers of the 2175 Å UV bump
arXiv:1002.3529 · doi:10.1088/2041-8205/712/1/L16
Abstract
Mixtures of polycylic aromatic hydrocarbons (PAHs) have been produced by means of laser pyrolysis. The main fraction of the extracted PAHs were primarily medium-sized, up to a maximum size of 38 carbon atoms per molecule. The use of different extraction solvents and subsequent chromatographic fractionation provided mixtures of different size distributions. UV-VIS absorption spectra have been measured at low temperature by matrix isolation spectroscopy and at room temperature with PAHs as film-like deposits on transparent substrates. In accordance with semi-empirical calculations, our findings suggest that large PAHs with sizes around 50 to 60 carbon atoms per molecule could be responsible for the interstellar UV bump at 217.5 nm.
6 pages, 4 Postscript figures, published in Astrophys. J. Lett. (2010)
References in corpus (5)
- Infrared Emission from Interstellar Dust. IV. The Silicate-Graphite-PAH Model in the Post-Spitzer Era
- On-line database of the spectral properties of polycyclic aromatic hydrocarbons
- Formation and destruction of polycyclic aromatic hydrocarbon clusters in the interstellar medium
- The role of the charge state of PAHs in ultraviolet extinction
- Dehydrogenated polycyclic aromatic hydrocarbons and UV bump