Deuterium, a swiss-knife to study star formation
by: Laurent Pagani (Observatory of Paris)
From the moment gas and dust concentrate enough to self-shield against UV, molecules form, temperature drops and cores collapse to form protostars, proto-planetary disks and (at least once) inhabited planets. To understand this evolution, we try to study the different phases with radiotelescopes and IR satellites mostly. We try to understand how long the clouds live, how the prestellar cores form, and finally whether the water on Earth came from comets or not. Deuterium, though playing no major role in all this, appears to be very helpful to understand several aspects of this story. I will illustrate its use with three different examples : cloud age, prestellar core formation speed and core depletion profile studies, all based on DCO+ and/or N2D+ observations and modelling, species for which the GBT now stands on the forefront of the observation tools.
