Session 91 - COBE and the Search for the Cosmic Infrared Background.
Oral session, Friday, January 09
Jefferson,

## [91.02] The COBE Diffuse Infrared Background Experiment Search for the Cosmic Infrared Background: II. Model of the Interplanetary Dust Cloud

T. Kelsall (NASA/GSFC), J. L. Weiland (HSTX), B. Franz (GSC), W. Reach (IPAC), H. T. Freudenreich (HSTX), E. Dwek (NASA/GSFC), M. G. Hauser (STScI), S. H. Moseley, R. F. Silverberg (NASA/GSFC)

The COBE Diffuse Infrared Background Experiment (DIRBE) surveyed the sky from 11 Dec. 1989 to 21 Sept. 1990 in 10 wavelength bands from 1.25 to 240 \mum. The absolute brightness of approximately 54observations per 0.32 deg x 0.32 deg pixel. These data reveal with high accuracy the apparent time variation of the zodiacal light due to the Earth's orbital motion. As part of the (DIRBE) search for the cosmic infrared background, we have developed an empirical parametric model for the interplanetary dust (IPD) cloud which reproduces the time-variation of these maps over the whole sky. The model includes scattering and emission contributions from a smooth IPD cloud, three pairs of asteroidal dust bands, and the circumsolar Earth-resonance ring. The results are internally consistent at the 1-3% level at all ten wavelengths. The model and its random and systematic uncertainties will be described.