Observations of extragalactic molecules. II. HCN and CS.
Abstract
Results are reported for searches for HCN and CS emission from NGC 253 and M82. The features observed in the J = 1-0 spectra of HCN show rough agreements of shape and velocity centroid with (C-12)O profiles, and imply HCN/CO abundance ratios that are close to Galactic values. The presence of HCN emission would support the hypothesis that massive molecular clouds (rather than small dust clouds) are the major contributors to the CO emission observed in these galaxies. No features were found in the J = 2-1 spectra of CS.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- June 1977
- DOI:
- 10.1086/155261
- Bibcode:
- 1977ApJ...214..390R
- Keywords:
-
- Carbon Compounds;
- Hydrocyanic Acid;
- Interstellar Matter;
- Radio Astronomy;
- Spectrum Analysis;
- Sulfides;
- Carbon Monoxide;
- Cassegrain Optics;
- Error Analysis;
- Radial Velocity;
- Astrophysics