Zodiacal light models with a bimodal population
Abstract
The compatibility of the observed properties of interplanetary dust grains in zodiacal light with a model made of two populations is investigated. Population 1 consists principally of large grains (with radius s greater than 2 microns) of density typical of silicates or chondritic materials in nearly circular orbit while Population 2 consists of small grains (s less than 2 microns) with typically metallic densities (abt 8 g/cu cm) in hyperbolic orbits. The spatial densities and volume scattering functions (VSF) of the two populations are deduced from the observed brightness of the zodiacal light. Though no clear-cut conclusions are reached, some general trends are detected: (1) the VSF of the zodiacal light is entirely compatible with the spatial density of grains obtained from lunar and space measurements. (2) Under all circumstances, the contribution of Population 2 appears to be non-negligible. (3) A minimum albedo of 0.5 (probably unrealistic) is required in order to explain the observed VSF with Population 1 alone on the basis of the model of Fresnel reflection plus an isotropic term.
- Publication:
-
Solid Particles in the Solar System
- Pub Date:
- 1980
- Bibcode:
- 1980IAUS...90...75L
- Keywords:
-
- Astronomical Models;
- Interplanetary Dust;
- Population Theory;
- Zodiacal Light;
- Doppler Effect;
- Grains;
- Particle Size Distribution;
- Spatial Distribution;
- Astronomy