Nitrogen Fractionation in Space
Scientific rationale
One of the current challenges in astrochemistry is to follow the chemical composition of a starless core during its evolution towards a planetary system and identify, in primitive objects of the Solar System, residual materials from the original cloud. Nitrogen, the fifth most abundant element in the Universe, exists naturally as a highly volatile gas (N2, N) and a mixture of compounds of different volatility (NH3, HCN, HNC, etc).
The nitrogen volatile isotopologues in the protosolar nebula may have been fractionated with respect to the original interstellar material. In our Solar System, any object (besides Jupiter) is enriched in 15N compared to the protosolar nebula. Large excesses in 15N have been found in organic material of chondrites and interplanetary dust particles. Species in cometary coma also appear to be 15N enriched.
The variations in the nitrogen isotopic composition in Solar System objects may be caused by a variety of effects, including Galactic nucleosynthesis, photochemical self-shielding, spallation reactions caused by the irradiation of the young sun and low temperature chemistry. If the effects of these mechanisms are properly understood, the relative abundances and isotopic compositions of the different N-bearing species in various astronomical sources may provide useful clues to the physical origin and early evolution of the Solar System.
The purpose of this two-day workshop is to gather different communities (astronomers, chemists, physicists) working on the problem of nitrogen isotopic fractionation in the interstellar medium to discuss the current understanding of different fractionation mechanisms, the variations between the objects in our Solar System, the link between the problems of N- and D-fractionation and the challenges observationally, theoretical and experimental that we are facing.
The workshop is organised by Charlotte Vastel and Jes Jørgensen within the framework of EU/COST network CM-1401 "Our Astrochemical Heritage" and hosted by Centre for Star and Planet Formation and the Niels Bohr Institute at University of Copenhagen.