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LibraryG.C. Sloan (Wyoming), G.L. Grasdalen (G-star Ent.), P.D. LeVan (Phillips Lab./GPOB)
1993b, ApJ, 409, 412
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We have observed HD 44179 and the surrounding unidentified infared (UIR) emission with a long-slit 10 µm spectrometer. By applying maximum entropy reconstruction techniques to our images, we have found spatial variations in the spectra not apparent inprevious work with beam sizes of several arcseconds diameter. We find that no UIR emission arises in the innermost regions of the source; instead, we observe only cool continuum emission. After its abrupt appearance 0.5" from the central source, the UIR emission decays steadily with distance, except for an enhancement in the intensity of the 11.3 µm feature ~1.5" away from the central source. The intensity of the 7.7 µm feature drops more quickly with distance than the intensity of the 8.6 and 11.3 µm features, and the wavelength of the peak intensity of this feature appears to shift from 7.9 µm near the central source to ~7.4 µm further away. These observations indicate that we have detected the formation of the carriers of the UIR emission features and changes in their emission properties as they move outward. In particular, the behavior of the 8.6 and 11.3 µm features suggest that the material is growing increasingly hydrogenated with distance. We suggest that all the unusual spectral properties of this system can be explained in terms of an accretion disk around a degenerate object.
This paper represents chapter 5 of Sloan's dissertation, and was a follow-up using maximum entropy reconstruction to Grasdalen et al. (1992).
Dissertation, Chapter 3 - Grasdalen et al. 1992, "Spatial structure in the 10 micron spectrum of HD 44179 (The Red Rectangle)"
Dissertation, Chapter 4 - Sloan et al. 1993a, "Spatially resolved spectra of silicate dust around alpha Orionis"
Last modified 27 May, 2008. © Gregory C. Sloan and others.