High NH2D/NH3 ratios in protostellar cores

  title={High NH2D/NH3 ratios in protostellar cores},
  author={Jennifer Hatchell},
  journal={Astronomy and Astrophysics},
  • J. Hatchell
  • Published 27 February 2003
  • Physics
  • Astronomy and Astrophysics
Observations of low mass protostars which probe small enough size scales to be within likely CO depletion regions show the highest [NH 2 D]/[NH 3 ] ratios yet measured, of 4-33%. These molecular D/H ratios are higher than those measured on larger scales, showing that deuterium fractionation increases towards protostellar cores. As in cold clouds, such high ratios can be produced by gas-phase ion-molecule chemistry in the presence of depletion. Grain surface chemistry is less likely to explain… 

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