Project P5: Dust opacity measurements for debris disks (AIU/Jena)


Dust particles in debris disks have, most likely, a complex composition and structure, which should determine, among other properties, their emissivity at the far-infrared and (sub-)millimeter wavelengths, at which they are observed. A safe interpretation of observational data at these wavelengths thus requires a profound knowledge of various optical material data and of the optics of such complex particle structures. With this project, we aim at determining optical data for possible dust constituent materials in the relevant wavelength and temperature range, and at measuring the opacity of complex dust mixtures as benchmark results for optical models. In terms of underlying physics, the first issue addresses mainly the influence of temperature and of structural defects on absorption indices of individual materials, while with the second we will investigate the influence of strongly absorbing admixtures on the effective absorption cross section. We will closely collaborate with projects P6 and P8 for the choice of materials and the comparison of results. The measured opacities and temperature-dependent sets of optical constants will be forwarded to the other projects.