MOLECULAR UNIVERSE

The research methodology of the Consortium is highly complementary and the research in the different areas is deeply interwoven. The fundamental molecular data acquired under this program will be made available to the whole scientific community through databases accessible through a special webportal.

Identification of specific species in space requires direct comparison of the particular frequencies of emission or absorption lines observed in interstellar space with laboratory spectroscopy measurements of known species in a controlled laboratory experiment supported by molecular physics quantum chemical calculations. The observed line intensities depend directly on the collisional excitation rates of the molecules with the predominant collision partners, atomic or molecular hydrogen and helium. These rates can be calculated using molecular physics methods or can be measured in the laboratory. Astronomical models can then be used to determine the physical conditions and the abundances of the molecules involved in the interstellar regions where the emission or absorption arises. The abundances of interstellar molecules are the result of a balance between formation and destruction reactions. The rate coefficients and products of relevant reactions can be measured in the laboratory or calculated using molecular physics tools. Once specific chemical routes have been identified and the relevant reaction rate coefficients measured or calculated, astronomical models can predict abundances of new species. Laboratory spectroscopy can then provide their transition frequencies while molecular physics can calculate their excitation rate coefficients. All of these data together can then be used in astronomical models to predict the expected line intensities of new species, which can then be targeted in specific searches.