Infrared Lines From Shocked Galactic Gases

Modest modification could convert the Small Helium-Cooled Infrared Telescope from a broad passband to a spectroscopic instrument for use on future Spacelab reflights. The goal of a spectroscopic survey would be the study of the energy budget the Galaxy allocates to shocks in neutral gas. Observational and theoretical studies to date indicate that shocks are common phenomena in neutral gas regions surrounding supernova explosions and nova outbursts, in clouds that border exoanding shells of planetary nebulae and HII regions, and in gases near stars that suffer rapid mass loss. This investigation would be conducted by surveying the Galaxy in three of the most prominent emission lines known to originate from post-shocked gas, the 6.9 μ m line of H2, the 63.2 μm line of [01], and the 157.4 μm [CII] line. Changes to the Present instrument would include replacement of its current optics by spectrometer optics of a design used successfully in repeated airborne observations. Existing electronics, methods of scanning the sky, data collection, and data analysis could otherwise remain the same.