Modelling the IRAS Zodiacal Emission

M. Rowan-Robinson, J. Hughes, K. Vedi, D. W. Walker
Astronomy Unit
Queen Mary and Westfield College
Mile End Road
London E1 4NS
U. K.

Abstract

Using version 3 of the IRAS Zodiacal History File, we investigated the spatial distribution of zodiacal dust at distances greater than 0.9 AU from the Sun. After investigating several hundred models for the density distribution of the interplanetary dust, the best fit to the data at |beta| > 15 degrees was found to be a simple fan model with a=4.9. The inclination of the symmetry plane of the dust to the ecliptic plane was found to be i=1.1 degrees, and the longitude of its ascending node was Omega=79 degrees. An isotropic 100 micron component was included in the model, but its magnitude, 2.2 MJy/sr, is not considered to be statistically significant in the light of the +/-1.6 MJy/sr uncertainty in the IRAS calibration at 100 microns.

M. Rowan-Robinson, J. Hughes, K. Vedi, and D. W, Walker, Modelling the IRAS Zodiacal Emission, Monthly Notices of the Royal Astronomical Society, Vol. 246, pages 273-278, 1990.