Abstract

In the mid-IR (MIR) region there is often an excess radiation due to circumstellar or diffusely distributed interstellar matter and there are distinguished diagnostic spectral features. These bear information on the chemical and physical nature of the intervening solid particles (refractory materials and ices) and are indicative of the presence of shock fronts, e.g. In case of comets, information on the dust production rate and physical properties of cometary nuclei can be derived. From all these fields there is a strong need for mid-infrared imaging, as well as spectroscopic and polarimetric observations with high spatial and spectral resolution of objects such diverse as from solar system bodies, as e.g. comets, to active galactic nuclei. All this refers to the spectral regions at the 10 and 20-µm band, the astronomical N- and Q-bands corresponding to the atmospheric windows ranging from 7.5 to 13.3µm and 16 to 24µm respectively.

© 1998 Optical Society of America