A search for the J = 1 --> 0 transition of l4CO.
Abstract
New and improved upper limits for the intensity of the J = 1-0 transition of /C-14/O in seven sources are determined. Five of these clouds represent star-formation zones, and the remaining two are supernovae remnants associated with relatively high CO antenna temperatures. The observations were taken with the NRAO-11 m antenna at Kitt Peak during November 1981. Although the noise levels achieved are extremely low, no evidence of /C-14/O emission in any of the sources investigated is found. Two-sigma upper limits for the C-14/C-12 ratio are found which are between 1.2 and 4.4 x 10 to the -5th in five star formation zones, and of order 10 to the -4th and greater for the SNRs S 147 and IC 443.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 1983
- DOI:
- 10.1093/mnras/202.2.265
- Bibcode:
- 1983MNRAS.202..265P
- Keywords:
-
- Abundance;
- Carbon Monoxide;
- Carbon 14;
- Electron Transitions;
- Milky Way Galaxy;
- Molecular Clouds;
- Supernova Remnants;
- Carbon 12;
- Astrophysics