Model of light scattering by dust particles in the solar system: Applications to cometary comae and planetary regoliths
Autor: | Kari Lumme, Antti Penttilä |
---|---|
Rok vydání: | 2011 |
Předmět: |
Physics
Radiation 010504 meteorology & atmospheric sciences Linear polarization Scattering Astrophysics Polarization (waves) 01 natural sciences Atomic and Molecular Physics and Optics Light scattering Computational physics Spherical geometry 0103 physical sciences Light scattering by particles SPHERES 010303 astronomy & astrophysics Spectroscopy 0105 earth and related environmental sciences Cosmic dust |
Zdroj: | Journal of Quantitative Spectroscopy and Radiative Transfer. 112:1658-1670 |
ISSN: | 0022-4073 |
DOI: | 10.1016/j.jqsrt.2011.01.016 |
Popis: | We analyze both the intensity and linear polarization of cosmic dust particles by using the physically exact superposition T-matrix method in a fixed orientation for various aggregates of spheres and DDA for the aggregates of Gaussian random spheres. We study both the spherical geometry (in cometary comae) and cylindrical slabs (for regoliths) up to 2000 monomers with size parameters less than ∼3. It is straightforward to produce the observed linear polarization in both geometries while the typically convex and strong opposition spike seems to require wide regolith geometries. The dependence of various parameters on light scattering has also been studied in a rather detailed form. In applications to the cometary polarization we can fit the data in six colors from UV to the J band at a very good accuracy. We, however, emphasize that we do not claim our model to be unique. The most important parameters here are the refractive index and the size distribution of submicron particles. Rest of the parameters has only a minor role. We also found that it is critically important to use several realizations from any assumed particle geometry model because corresponding scattering characteristics can vary quite a lot. |
Databáze: | OpenAIRE |
Externí odkaz: |