Nearby Molecular Hydrogen

If the gas-to-dust ratio is sufficiently uniform throughout the local interstellar medium, galaxy counts may provide a useful probe of the large scale structure of the interstellar gas. This idea substantiated by gamma ray observations led to the discovery of nearby molecular cloud complexes. The reddening studies indicate that one of them lies between 80 and 140 pc from the Sun. From CO observations, its molecular mass is estimated to be a few 1000 stellar mass units.