A. Aguilar
R.S. Mangina
G.K. James
P. Geissler
L. Trafton
J.M. Ajello
2008
<p>We investigated the electron impact–induced fluorescence spectrum of SO<sub>2</sub><span> to provide excitation cross sections for modeling Io's emission spectrum and analyzing Cassini Imaging Science Subsystem observations. The electron-excited middle-ultraviolet visible optical near-infrared (VOIR) emission spectrum of SO</span><sub>2</sub><span> gas was generated in the laboratory and studied from 2000 to 11,000 Å at a resolution of Δ<i>λ</i> ∼ 2.5 Å full width at half maximum (FWHM). The VOIR laboratory spectrum longward of 6000 Å consists entirely of S I, II and O I, II multiplets for electron impact energies above ∼15 eV. Between 2000 and 6000 Å, we find previously identified molecular bands from both SO and SO</span><sub>2</sub>. This work represents a significant improvement in spectral resolution over our earlier work done at 18 Å FWHM. From a measurement of the medium-resolution spectrum, we provide detailed 25- and 100-eV emission cross sections for spectral features from 2000 to 11,000 Å. On the basis of these data, we suggest future ground-based and satellite telescopic observations in the VOIR that are of promise for understanding Io's atmosphere.</p>
application/pdf
10.1029/2007JE002921
en
American Geophysical Union
Middle UV to near-IR spectrum of electron-excited SO<sub>2</sub>
article