MOLECULAR UNIVERSE

1. Ionisation and star formation
Ion-molecule reactions are strongly promoted by the Coulomb interaction even at low interstellar temperatures but very little is known experimentally about the rates or products of reactions involving electrons, ions and large anionic, neutral or cationic PAHs or carbon chains. To this end, laboratory astrochemistry and astronomical modelling will work hand in hand in order to explore the interaction between ions, electrons and large molecules and to address the larger astronomical question of star formation.

2. Nitrogen chemistry as tracers of protostellar condensations
The rate at which nitrogen is broken out of N₂ and incorporated into less volatile species determines the rate at which the gas phase loses its molecular signature. Studies of the reactivity and excitation of nitrogen-bearing species, as well as their spectroscopy, may thus provide the only way to determine the physical conditions and dynamics of the phase preceding the collapse phase of star formation.

3. Molecular tracers of shocks
Collisional excitation rates of Sulphur monoxide, sulphur dioxide as well as silicon monoxide are poorly known, considerably hampering the analysis of astronomical data in terms of the local physical conditions (density and temperature of the gas), as well as the abundances of these shock tracers. A combined programme on the chemistry of sulphur- and silicon-bearing species, their abundances, their excitation, and their spectroscopic signatures under astrophysically relevant conditions will enable the interaction of protostars with their “natal” environment to be probed.