DIRBE 1-240 $\mu$m IR Observations of H II Regions

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Session 60 -- HII Regions
Display presentation, Thursday, 9:20-4:00, Pauley Room

[60.08] DIRBE 1-240 $\mu$m IR Observations of H II Regions

P.M. Mitra (GSC/NASA), R.G. Arendt (ARC/NASA), M.G. Hauser, N. Boggess, E. Dwek, T. Kelsall, S.H. Moseley, R.F. Silverberg (NASA/GSFC)

The Diffuse Infrared Background Experiment (DIRBE) instrument aboard the Cosmic Background Explorer (COBE) satellite surveyed the entire sky in ten spectral bands ranging from 1 $\mu$m to 240 $\mu$m at a spatial resolution of ~0.7 degrees. The broadband DIRBE observations and the results of their analysis are presented for several bright H II regions (e.g., Orion A, Rosette, $\rho$ Oph). Surface brightness maps in all ten bands as well as color maps of the H II regions are shown. The large spectral range of the observations facilitate accurate estimates of the total IR luminosity, and allows spectral decomposition. The energy spectrum of each H II region is constructed. It is found that the dust emission must be modelled using at least three grain components. The components are similar to those in the model proposed by Desert et al (A \& A, 237, 215-236, 1990) -- PAH, very small grains, and large grains. The bolometric luminosity, IR colors, and other physical properties are discussed. \\ COBE is managed by the Goddard Space Flight Center, under the guidance of the COBE Science Working Group, and sponsored by NASA's Astrophysics Division, Office of Space Science, Washington, DC.

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