Observations of Cumulene Carbenes, H_2CCCC and H_2CCC, in TMC-1
Abstract
The carbon chain molecule H_2CCCC was detected in the dark cloud TMC-1 for the first time in the course of a molecular line survey using the Nobeyama 45-m telescope. From nine transitions observed in the frequency region of 17--45 GHz, the total column density of H_2CCCC in TMC-1 was derived to be 7.5(+/- 2.0)times 10(12) cm(-2) , which is about half of the value reported in IRC+10216. Five transitions of a related carbon chain molecule, H_2CCC, were also detected in TMC-1. The column density of H_2CCC obtained in TMC-1, 2.8(+/- 0.9)times 10(12) cm(-2) , is a factor of three smaller than that of H_2CCCC. The ortho-to-para abundance ratios of H_2CCCC and H_2CCC were found to be 4.2(+/- 1.5) and 5.9(+/- 2.0), respectively. The chemical reactions of these carbon-chain molecules in dark clouds are discussed.
- Publication:
-
Publications of the Astronomical Society of Japan
- Pub Date:
- August 1991
- Bibcode:
- 1991PASJ...43..607K
- Keywords:
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- Carbenes;
- Dark Matter;
- Interstellar Matter;
- Molecular Chains;
- Molecular Clouds;
- Abundance;
- Interstellar Chemistry;
- Molecular Energy Levels;
- Ortho Hydrogen;
- Para Hydrogen;
- Taurus Constellation;
- Astrophysics;
- DARK CLOUD CHEMISTRY;
- INTERSTELLAR MOLECULES;
- TMC-1