AAS 199th meeting, Washington, DC, January 2002
Session 97. Interstellar Medium - III
Display, Wednesday, January 9, 2002, 9:20am-6:30pm, Exhibit Hall

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[97.12] Infrared Emission from Interstellar Dust in the Small Magellanic Cloud

B.T. Draine, A. Li (Princeton University Observatory)

The silicate/graphite-PAH emission model (Li & Draine 2001) is shown to be applicable to dust in the Small Magellanic Cloud (SMC). The mid-IR emission spectrum of the quiescent molecular cloud SMC B1#1 -- characterized by an unusually high 11.3\mum/7.7\mum band ratio (Reach et al.\ 2000) -- can be explained by PAHs which are mostly neutral, without invoking a higher degree of hydrogenation than for Galactic PAHs. It is also shown that the present dust model is able to reproduce the COBE/DIRBE and IRAS spectral energy distribution from near-IR to far-IR for the SMC B1#1 cloud, as well as for the SMC as a whole. The PAH abundance required in SMC B1#1 is an order of magnitude greater than for the SMC as a whole. The PAH column density required to account for the mid-IR emission spectrum is expected to contribute a 2175Å\ extinction excess of ~0.5 mag through SMC B1#1.

This research was supported by NASA grant NAG5-7030 and NSF grants AST-9619429 and AST-9988126.

References: Li, A., & Draine, B.T. 2001, ApJ, 554, 778. Reach, W.T., Boulanger, F., Contursi, A., & Lequeux, J. 2000, A&A, 361, 895.

The author(s) of this abstract have provided an email address for comments about the abstract: draine@astro.princeton.edu

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