Session 15 - Interstellar Medium I.
Display session, Monday, January 15
North Banquet Hall, Convention Center

## [15.03] An Investigation of the Far-Infrared Emission of the Galaxy with DIRBE

S. L. Snaith (Agnes Scott College/WIRO), D. R. Ciardi, R. R. Thompson (U. Wyoming/WIRO)

We present a study of the diffuse infrared emission of the local interstellar medium for the region 42^\circ \leq l \leq 146^\circ and 10^\circ \leq b \leq 50^\circ. The study was performed using the DIRBE 90^\circ elongation data at 60\mum, 100\mum, 140\mum and 240\mu. We have used a simple cosecant law for zodiacal emission removal and have calculated the mean flux density ratios for the six colors. It is found that the I_60-I_100, I_60-I_140 and I_60-I_240 flux density ratios deviate from the mean flux density ratios as a function of galactic longitude by an average of 36%, 50%, and 58%, respectively. The I_100-I_140, I_100-I_240 and I_140-I_240 ratios show a similar but weaker longitude dependence. This indicates that the smaller grains (a < 0.01\mum) in the diffuse interstellar medium have a more variable population density than the population density of the larger grains.