Chemical modelling of molecular sources - VI. Carbon-bearing molecules in oxygen-rich circumstellar envelopes.
Abstract
The authors present the results of a detailed chemical kinetic model of the expanding circumstellar envelope of a cool oxygen-rich star. Parent molecules injected into the envelope are photodissociated by the external interstellar radiation field and neutral-neutral reactions between radicals, in particular OH, determine the chemical composition of the envelope. The authors show that the recent detection of HCN in several oxygen-rich envelopes can only be understood if a source of carbon other than CO, most probably methane, is injected into the envelope with an abundance much greater than that predicted by LTE chemistry. They suggest several observational consequences of their model.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- January 1988
- DOI:
- 10.1093/mnras/230.1.79
- Bibcode:
- 1988MNRAS.230...79N
- Keywords:
-
- Carbon Compounds;
- Cool Stars;
- Interstellar Chemistry;
- Photodissociation;
- Stellar Envelopes;
- Abundance;
- Hydrocyanic Acid;
- Methane;
- Nitric Oxide;
- Oxygen;
- Astrophysics