Depletion of heavy nitrogen in the cold gas of star-forming regions

  title={Depletion of heavy nitrogen in the cold gas of star-forming regions},
  author={Kenji Furuya and Yuri Aikawa},
  journal={arXiv: Astrophysics of Galaxies},
We investigate nitrogen isotope fractionation in forming and evolving molecular clouds using gas-ice astrochemical simulations. We find that the bulk gas can become depleted in heavy nitrogen (15N) due to the formation of 15N-enriched ices. Around the chemical transition from atomic nitrogen to N2, N15N is selectively photodissociated, which results in the enrichment of 15N in atomic nitrogen. As 15N-enriched atomic nitrogen is converted to ammonia ice via grain surface reactions, the bulk gas… 

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