Carbon in Comet Bradfield 1979l
Abstract
Ultraviolet spectra of comet Bradfield obtained with IUE show a surprising absence of CO(+) despite the presence of CO2(+), and they also show, for the first time, the unambiguous presence of the Mulliken bands of C2. With the use of simultaneous ground-based data, a value of 0.00001 is derived for the transition moment of the a 3 Pi-X 1 Sigma g + transition of C2. The anomalous CO(+)/CO2(+) ratio can be accounted for by the different scale lengths of the species rather than by an abundance difference. Using the model of Feldman (1978), the upper limit for CO(+) is found to be consistent with the observed abundance of CO. On that same model, however, CO cannot produce nearly as much atomic carbon as is observed.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- December 1980
- DOI:
- 10.1086/183429
- Bibcode:
- 1980ApJ...242L.187A
- Keywords:
-
- Abundance;
- Carbon;
- Comets;
- Ultraviolet Spectra;
- Brightness;
- Carbon Dioxide;
- Carbon Monoxide;
- Iue;
- Positive Ions;
- Astronomy