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Title: TOWARD A UNIQUE NITROGEN ISOTOPIC RATIO IN COMETARY ICES

Journal Article · · Astrophysical Journal Letters
; ;  [1]; ; ; ;  [2]; ; ; ; ;  [3]
  1. Institut UTINAM-UMR CNRS 6213, Observatoire des Sciences de l'Univers THETA, University of Franche-Comté, BP 1615, F-25010 Besançon Cedex (France)
  2. Synchrotron SOLEIL, ligne AILES, UMR 8214 CNRS, L'orme des Merisiers, Saint-Aubin, F-91192 Gif-Sur-Yvette (France)
  3. Département d'Astrophysique, de Géophysique et d'Océanographie, Université de Liège, Allée du Six Août, B-4000 Liège (Belgium)

Determination of the nitrogen isotopic ratios in different bodies of the solar system provides important information regarding the solar system's origin. We unambiguously identified emission lines in comets due to the {sup 15}NH{sub 2} radical produced by the photodissociation of {sup 15}NH{sub 3}. Analysis of our data has permitted us to measure the {sup 14}N/{sup 15}N isotopic ratio in comets for a molecule carrying the amine (-NH) functional group. This ratio, within the error, appears similar to that measured in comets in the HCN molecule and the CN radical, and lower than the protosolar value, suggesting that N{sub 2} and NH{sub 3} result from the separation of nitrogen into two distinct reservoirs in the solar nebula. This ratio also appears similar to that measured in Titan's atmospheric N{sub 2}, supporting the hypothesis that, if the latter is representative of its primordial value in NH{sub 3}, these bodies were assembled from building blocks sharing a common formation location.

OSTI ID:
22364055
Journal Information:
Astrophysical Journal Letters, Vol. 780, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English