Showing papers by "William T. Reach published in 1991"
TL;DR: In this paper, the location and brightness of the peak zodiacal emission were derived from IRAS observations of the diffuse infrared background radiation, from which the orientation of the surface of maximum dust density near the earth's orbit was derived.
Abstract: The location and brightness of the peak zodiacal emission are derived from IRAS observations of the diffuse infrared background radiation. A uniform ellipsoid geometrical model is fitted to the latitudes of peak brightness, from which the orientation of the surface of maximum dust density near the earth's orbit is derived. Deviations from the uniform ellipsoid indicate that this surface bends toward the invariable plane of the solar system beyond 2.5 AU from the sun. The variations of the peak zodiacal emission brightness with solar elongation and observation date allow two independent determinations of the gradient of the volume emissivity of interplanetary dust. Combined with theoretical calculations of the infrared emission from silicate and graphite grains heated by the sun, the gradient of the dust density is found to be n proportional to r exp (-1.1 + or - 0.2). Systematic brightness variations with ecliptic longitude reveal two potential asymmetries in the dust complex: excess emission following the earth in its orbit, and excess emission along lines of sight with ecliptic longitude lambda = 190 + or - 20 deg and solar lambda about 100 deg.
38 citations
01 Jan 1991
TL;DR: The contribution of the infrared background by asteroidal dust, distinguished both by lower color temperature and "band-pair" morphology, was determined using IRAS observations as mentioned in this paper, indicating that asteroid families and groups are the source of asteroidal Dust.
Abstract: The contribution to the brightness of the infrared background by asteroidal dust, distinguished both by lower color temperature and ‘band-pair’ morphology, is determined using IRAS observations. Dust band pairs are associated with at least 7 asteroid families and groups, but very little is detected from the remainder of the asteroid belt, indicating that asteroid families and groups are the source of asteroidal dust.
3 citations