Lis, D. C. and Wootten, A. and Gerin, M. and Roueff, E. (2010) Nitrogen Isotopic Fractionation in Interstellar Ammonia. Astrophysical Journal Letters, 710 (1). L49-L52. ISSN 0004-637X http://resolver.caltech.edu/CaltechAUTHORS:20100301-092329398
- Published Version
See Usage Policy.
Use this Persistent URL to link to this item: http://resolver.caltech.edu/CaltechAUTHORS:20100301-092329398
Using the Green Bank Telescope, we have obtained accurate measurements of the ^(14)N/^(15)N isotopic ratio in ammonia in two nearby cold, dense molecular clouds, Barnard 1 and NGC 1333. The ^(14)N/^(15)N ratio in Barnard 1, 334 ± 50 (3σ), is particularly well constrained and falls in between the local interstellar medium/proto-solar value of ~450 and the terrestrial atmospheric value of 272. The NGC 1333 measurement is consistent with the Barnard 1 result, but has a larger uncertainty. We do not see evidence for the very high ^(15)N enhancements seen in cometary CN. Sensitive observations of a larger, carefully selected sample of prestellar cores with varying temperatures and gas densities can significantly improve our understanding of the nitrogen fractionation in the local interstellar medium and its relation to the isotopic ratios measured in various solar system reservoirs.
|Additional Information:||© 2010 The American Astronomical Society. Received 2009 November 6; accepted 2009 December 30; published 2010 January 20. We thank T. Minter and the GBT operator, D. Stricklin, for their assistance during the observations and J. Braatz for his advice in setting up the observing scripts. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc. D. C. Lis is supported by the National Science Foundation grant AST-0540882 to the Caltech Submillimeter Observatory. M. Gerin and E. Roueff acknowledge support from the CNRS-INSU French National Program PCMI (Physique et Chimie du Milieu Interstellaire).|
|Subject Keywords:||astrochemistry; ISM: abundances; ISM: individual objects (Barnard 1, NGC 1333); ISM: molecules; molecular processes; radio lines: ISM|
|Official Citation:||Nitrogen Isotopic Fractionation in Interstellar Ammonia D. C. Lis, A. Wootten, M. Gerin, and E. Roueff 2010 ApJ 710 L49-L52 doi: 10.1088/2041-8205/710/1/L49|
|Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Tony Diaz|
|Deposited On:||02 Mar 2010 17:44|
|Last Modified:||26 Dec 2012 11:48|
Repository Staff Only: item control page