The 12C/13C isotope ratio toward zeta Ophiuchi.
Abstract
Observations of interstellar CH(+) toward Zeta Oph were performed to determine the C-12/C-13 isotope ratio in this diffuse cloud. The very high signal-to-noise ratio spectra yield 6 sigma detections of the (C-13)H(+) features at 4232 A and 3957 A; a weighted mean C-12/C-13 ratio of 43 + or - 6 (1 sigma) is obtained. The uncertainty includes the contribution of continuum placement errors, statistical channel-to-channel signal fluctuations, and the error introduced in deconvolving the blended isotopic lines at 4232 A. This result indicates a decrease in the local galactic C-12/C-13 ratio by a factor of 2 during the 4.6 billion yr since the formation of the sun.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1985
- DOI:
- 10.1086/184524
- Bibcode:
- 1985ApJ...294L.131H
- Keywords:
-
- Abundance;
- Interstellar Matter;
- Molecular Clouds;
- Ophiuchi Clouds;
- Carbon 12;
- Carbon 13;
- Line Spectra;
- Spectral Line Width;
- Astrophysics