Ultraviolet observations of interstellar molecules and grains fromSpacelab

Abstract

Listen

Translate article

Observational results obtained to date on interstellar grains and molecules are briefly reviewed, and several promising areas for further research withSpacelab are suggested. Regarding grains, useful data can be expected on the shape of the ultraviolet extinction curve for new interstellar regions; the nature of UV extinction at short wavelengths, down to the Lyman limit; the presence or absence of structure in the UV extinction curve comparable to the visible-wavelength diffuse bands; the scattering properties of grains in new kinds of clouds and nebulae; and the polarization properties of grains in UV wavelengths. The principal advances which may be expected in observations of molecules will include the ability to probe more heavily-obscured regions, where molecular species are more abundant than in the diffuse clouds observed to date; coverage of wavelength regions (such as λλ 1400–3200) not well-studied with previous instruments such asCopernicus; and the capability of observing in optical absorption species detected in the same line of sight in radio emission, which provides unique information on cloud geometry and physical conditions.