Studies of ionized carbon regions in dark clouds.
Abstract
Summary. Carbon recombination line emission was detected in only 6 out of 27 regions surveyed in dark clouds with the Parkes 64-m radiotelescope. Compact sources of relatively strong Cna line emission, such as those in rho Ophiuchus and NGC 2023, therefore appear to be rare. In most cases the non-detections were probably due either to a large dilution factor for the ionizing radiation, or to a low electron density in the cloud. The physical properties of those regions in which lines were detected are discussed; it is suggested that the ratio of sulfur to carbon line intensities may generally be higher in extended, -density regions, possibly because of a greater propensity for carbon atoms to accrete onto volatile dust grains. Key words: radio recombination lines - C II regions - dark clouds
- Publication:
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Astronomy and Astrophysics
- Pub Date:
- June 1979
- Bibcode:
- 1979A&A....76....1V
- Keywords:
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- C II Regions:Dark Clouds;
- Dark Clouds:Recombination Lines