Observations of interstellar HNC, DNC, and HN/sup 13/C: Temperature effects on deuterium fractionation

Journal Article · Thu Mar 15 04:00:00 EST 1979 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/156900· OSTI ID:6251411

Snell, R L; Wootten, A

We report here an extensive search for DNC emission in 18 clouds with HNC emission. The DNC molecule was found in 13 of these clouds. The HN/sup 13/C molecule was also sought in those clouds where saturation was thought to be important. We have determined the (DNC)/(HNC) ratios incorporating the effects of saturation and radiation trapping. The extent of deuteration found in HNC is larger than for any other molecule yet observed. The (DNC)/(HNC) ratios are also found to strongly anticorrelate with the kinetic temperature of the cloud, suggesting that exchange reactions between HD and a molecular ion are ultimately responsible for the deuteration. The value of ..delta..E/k for the exchange reaction that produces DNC is determined to be 240 +- 60 K. Low values for the abundance of electrons and certain neutral species are similar to those determined from (DCO/sup +/)/(HCO/sup +/) and (N/sub 2/D/sup +/)/(N/sub 2/H/sup +/).

• Research Organization: Department of Astronomy and Electrical Engineering Research Laboratory, University of Texas at Austin
• OSTI ID: 6251411
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 228:3; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CHEMICAL COMPOSITION
CHEMICAL REACTIONS
CHEMISTRY
COSMOCHEMISTRY
DEUTERIUM
FRACTIONATION
HYDROCYANIC ACID
HYDROGEN COMPOUNDS
HYDROGEN ISOTOPES
INORGANIC ACIDS
INTERSTELLAR SPACE
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
MOLECULES
NUCLEI
ODD-ODD NUCLEI
SEPARATION PROCESSES
SPACE
STABLE ISOTOPES