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L. S. Bernstein (Spectral Sciences, Inc.), D. K. Lynch (The Aerospace Corporation), A. Berk (Spectral Sciences, Inc.), R. W. Russell (The Aerospace Corporation)
We present a model for interstellar grains that is able to closely reproduce the observed UIR spectral features at 3.3, 6.2, 7.7, 8.6, and 11.3 µm. The particles consist of highly porous "closed-cell" siliceous or carbonaceous foam that holds and retains molecules of H20, CH4, SiO and SiH4 in its interior. Surface interactions between the trapped molecules and interior grain surfaces result in pressure broadening and frequency shifts. The pressure broadening is sufficiently high to produce smooth spectral contours for the molecular vibration-rotation emission bands. The small grains (20 nm) are heated by absorbing single UV photons. The stability, lifetime, chemistry, composition and formation of MIGs are discussed in the context of astrophysical possibility.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.