Chair: Charlotte Vastel
Co-chair: Octavio Roncero
In comets, inter planetary materials and carbonaceaous chodrites meteorites, as well as star forming regions in various evolutionary stages (from pre-stellar cores to protostars to protoplanetary disks), molecular species have been found enriched in the heavy isotopes deuterium (D) and nitrogen-15 with deuterium enrichments wildly varying, from 1 to 13 orders of magnitude. There is also a general tendency for organic molecules to display larger D-fractions compared to water while 15 N-fractionation is more active in nitrile- than amine-bearing molecules. Recent results from the Herschel Space Observatory have shown that the HDO/H2O abundance ratio in comets is essentially the same as that in our oceans (about ten times larger than the D/H cosmic ratio). The observational tools (spectroscopy, collisional rates) and theoretical tools are to be developed to understand both existing observations, forthcoming ones and actual experimental data.