Isotope abundances in interstellar molecular clouds

Journal Article · Sun Feb 15 04:00:00 EST 1976 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/154147· OSTI ID:7365093

Wannier, P G; Penzias, A A; Linke, R A; Wilson, R W

The J=1..-->..J=0 transition of carbon monoxide is used to study the abundance ratios of carbon and oxygen isotopes in dense molecular clouds. Very high-quality spectra were obtained of /sup 12/C/sup 16/O (CO), /sup 13/C/sup 16/C(/sup 13/CO), and /sup 12/C/sup 18/O(C/sup 18/O) in 14 regions distributed throughout the galactic plane. Effects of line saturation are carefully examined, and it is found that the /sup 13/CO species often produces a slightly saturated line. When saturation is properly taken into account, the data from all the regions cluster about a single value of approx.14 for the /sup 13/C/sup 16/O//sup 12/C/sup 18/O abundance ratio. This value is significantly different from the corresponding terrestrial ratio of 5.6, and the difference probably results from chemical evolution having occurred in the Galaxy since the birth of the solar system. The results of additional isotope studies which indicate that the value of /sup 12/C//sup 13/C is approx.40 as compared with the terrestrial value of 89 are presented. (AIP)

• Research Organization: Bell Telephone Laboratories, Crawford Hill Laboratory, Holmdel, New Jersey
• OSTI ID: 7365093
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 204:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARBON 12
CARBON 13
CARBON COMPOUNDS
CARBON ISOTOPES
CARBON MONOXIDE
CARBON OXIDES
CHALCOGENIDES
CHEMISTRY
COSMOCHEMISTRY
EVEN-EVEN NUCLEI
EVEN-ODD NUCLEI
INTERSTELLAR SPACE
ISOTOPE RATIO
ISOTOPES
LIGHT NUCLEI
MOLECULES
NEBULAE
NUCLEI
OXIDES
OXYGEN 16
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
SPACE
STABLE ISOTOPES