Previous abstract Next abstract
For interstellar grains, very little has been established with regard to how variations in ultraviolet extinction correlate with variations in infrared emission. In particular, it is of interest to ask whether variations in linear UV extinction, 0.2175 micron bump strength, and far-UV rise correlate with variations in the relative emission of small and large grains at mid- and far-infrared wavelengths or large grain equilibrium temperatures. To address these issues, we present the results of a UV extinction study of several bright visual reflection nebulae studied previously at mid- and far-infrared wavelengths (Sellgren, Werner, and Luan 1990) and Casey (1991). The extinction curves are based upon data from the IUE archive assuming the unreddened stellar continuums from the Wu and Heck UV catalogs. The resultant extinction curves are decomposed according to the parametric formulation of Fitzpatrick and Massa 1990). We discuss the extent to which variations in nebular extinction are consistent with inferred variations in the nebular abundance of very small grains.
Friday program listing