Hostname: page-component-77c89778f8-vsgnj Total loading time: 0 Render date: 2024-07-22T03:27:52.196Z Has data issue: false hasContentIssue false

Measurements of Isotopic Abundances in Interstellar Clouds

Published online by Cambridge University Press:  14 August 2015

Arno A. Penzias*
Affiliation:
Bell Telephone Laboratories, Holmdel, N. J.

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

While an examination of the available data reveals some seemingly contradictory results, a general framework having the following outlines can be put forward:

1. With the exception of the two galactic center sources SgrA and SgrB, the relative isotopic abundances exhibited by the giant molecular clouds in our Galaxy exhibit few, if any, significant variations from the values obtained by averaging the data from all these sources.

2. The 13C/12C and 14N/15N abundance ratios are ∼130% and ∼150%, respectively, of their terrestrial values throughout the galactic plane and somewhat higher, ∼300%, near the galactic center.

3. The 16O/18O and 17O/18O abundance ratios are ∼130% and ∼160%, respectively, of their terrestrial values throughout the Galaxy, although the former may be somewhat lower near the galactic center.

4. The S and Si isotopes have generally terrestrial abundances.

Type
Research Article
Copyright
Copyright © Reidel 1980 

References

Cernicharo, J., and Guelin, M.: 1979, in preparation.Google Scholar
Frerking, M.A.: 1979, in preparation.Google Scholar
Frerking, M.A., Wilson, R.W., Linke, R.A., Wannier, P.G.: 1979, submitted to Ap. J.Google Scholar
Gardner, F.F., and Whiteoak, J.B.: 1979, MNRAS 188, p. 331.Google Scholar
Goldsmith, P.F., and Linke, R.A.: 1979, to be published.Google Scholar
Guelin, M., and Thaddeus, P.: 1979, Ap. J. (Letters) 227, p. L139.Google Scholar
Henkel, C., Walmsley, C.M., and Wilson, T.L.: 1979A, Astron. and Astrophys., in press.Google Scholar
Henkel, C., Wilson, T.L., and Downes, D.: 1979B, Astron. and Astrophys. 73, p. L13.Google Scholar
Kutner, M.L., Machnik, D.E., Tucker, K.D., and Massano, W.: 1979, to be published.Google Scholar
Langer, W.D., Goldsmith, P.F., Carlson, E.R., and Wilson, R.W.: 1980, Ap. J., in press.Google Scholar
Lazareff, B., Lucas, R., and Encrenaz, P.: 1978, Astron. and Astrophys. 70, p. L77.Google Scholar
Linke, R.A., Goldsmith, P.F., Wannier, P.G., Wilson, R.W., and Penzias, A.A.: 1977, Ap. J. 214, 50.Google Scholar
Linke, R.A.: 1979, in preparation.Google Scholar
Penzias, A.A.: 1979, in preparation.Google Scholar
Stark, A.A.: 1979, to be published.Google Scholar
Tucker, K.D., Kutner, M.L., and Massano, W.: 1979, Ap. J. (Letters) 227, L143.Google Scholar
Wannier, P.G.: 1977, CNO Isotopes in Astrophysics , Audouze, J., Ed. D. Reidel, p. 71.Google Scholar
Wannier, P.G., and Linke, R.A.: 1977, Ap. J. 214, p. 50.Google Scholar
Wannier, P.G., and Linke, R.A.: 1978, Ap. J. 226, p. 817.Google Scholar
Whiteoak, J.B., and Gardner, F.F.: 1975, Proc. Astr. Soc. Aust. 2, 360.CrossRefGoogle Scholar
Whiteoak, J.B., and Gardner, F.F.: 1978, MNRAS 183, p. 67p.CrossRefGoogle Scholar
Wilson, R.W., Penzias, A.A., Wannier, P.G., and Linke, R.A.: 1976, Ap. J. (Letters) 204, p. L135.Google Scholar
Wilson, T.L., Walmsley, C.M., Henkel, C., Pauls, T., Mattes, H.: 1979, Astron. and Astrophys., in press.Google Scholar
Wolff, R.S.: 1979, Ap. J., in press.Google Scholar