Observations of HC5N and HC7N in SGR B2 and Cloud 2
Abstract
We present observations of the J = 3 → 2 transition of HC5N and of the J = 7 → 6 transition of HC7N in Sgr B2 and Cloud 2. In Sgr B2 we confirm the results of Avery et al. (1979) indicating that several of the low J lines of HC5N are weak masers. The intensities of the hyperfine components of HC5N measured in Cloud 2 agree with the expected thermal ratios, and the available data were satisfactorily fitted to a simple local thermodynamic equilibrium model with a column density of 1.6 × 1014 and an excitation temperature of 15K. HC7N was not detected in Sgr B2. The J = 7 → 6 transition of HC7N measured in Cloud 2 gives a [HC5N/HC7N] abundance ratio of 7±3.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 1980
- DOI:
- 10.1093/mnras/192.4.651
- Bibcode:
- 1980MNRAS.192..651R
- Keywords:
-
- Electron Transitions;
- Hydrocyanic Acid;
- Interstellar Matter;
- Molecular Spectra;
- Radiative Transfer;
- Abundance;
- Hyperfine Structure;
- Interstices;
- Normal Density Functions;
- Thermodynamic Equilibrium;
- Astrophysics