Skip to main content
European Commission logo print header
Contenido archivado el 2022-12-23

Theoretical and experimental investigations of light scattering by heterogeneous non-spherical cosmic dust grains

Objetivo

The principal goals of the project are the development of a new generation of cosmic dust models and the creation of tools required in light scattering and radiative transfer. The main directions of the work are:

- Development of new exact and approximate theoretical methods to calculate scattering of radiation by particles of different shapes and structures.

- Laboratory measurements of light scattering characteristics for particles of various sizes, shapes, compositions.

- Creation of an electronic database containing information on the optical properties of particles.

- Development of numerical codes to simulate polarized radiation transfer by non-spherical aligned particles.

- Development of new models of cosmic dust grains as composite non-spherical particles and interpretation of the recent astrophysical observations of interstellar, circumstellar and interplanetary dust.

The research activities will include:

- Creation of new computer codes for calculations of the optical properties of inhomogeneous non-spherical particles; development of approximate methods; construction of new mixing rules of the Effective Medium Theories; detailed comparison of exact and approximate methods; determination of the range of validity of different approximations.

- Measurements of the extinction cross-sections and scattering matrix for analogues of cosmic dust grains; analysis of distinctions between the data obtained from experiments and theoretical calculations; a search for the analytical models reproducing experimental data.

- Computation of benchmark results for the optical properties of homogeneous/ inhomogeneous spherical/non-spherical particles in a wide range of parameter values; development of the electronic Database of Optical Properties and its filling with the benchmarks, original codes and other related resources.

- Creation of a Monte Carlo numerical code to calculate the transfer of polarized radiation for non-spherical aligned particles distributed around several illuminating sources; creation of a model describing the enhanced backscattering of light and polarization effects at small phase angles for closely packed media based on interference of double scattered waves.

- Creation of new models of interstellar dust grains as heterogeneous particles with tight constraints on element abundances; detailed interpretation of observations of evolved and young stars in the frame of the model of composite circumstellar grains; development of a new approach to cometary grains and simultaneous interpretation of observed effects; interpretation of the observed phase dependence of polarization for Saturn's rings.
The following results are expected:

- A series of new light scattering codes with full documentation and papers presenting the new algorithms and codes.

- A large set of experimental data for a variety of particle kinds, conclusions on their reliability, papers with the results and recommendations for different applications.

- The tables and plots with benchmark results for various small particles, the electronic database with a free access via the Internet.

- A Monte Carlo code and other polarized radiation transfer codes with full documentation and papers presenting the codes and their testing.

- Estimates of cosmic dust grain characteristics on the base of heterogeneous non-spherical particle models for interstellar clouds, circumstellar shells, cometary atmospheres, and Saturn's rings; papers presenting the results.

Convocatoria de propuestas

Data not available

Régimen de financiación

Data not available

Coordinador

University of Amsterdam
Aportación de la UE
Sin datos
Dirección
Kruislaan 403
1098 SJ Amsterdam
Países Bajos

Ver en el mapa

Coste total
Sin datos

Participantes (5)