Observations of HC/sub 3/N, HC/sub 5/N, and HC/sub 7/N in molecular clouds

Journal Article · Sun Feb 15 04:00:00 EST 1981 · Astrophys. J.; (United States)

DOI:https://doi.org/10.1086/158683· OSTI ID:6294609

Snell, R L; Schloerb, F P; Young, J S; Hjalmarson, A; Friberg, P

We present observations of HC/sub 3/N, HC/sub 5/N, and HC/sub 7/N in five molecular clouds. Statistical equilibrium calculations have been performed for HC/sub 5/N and HC/sub 7/N and compared with our data and data on other transitions of these molecules reported in the literature to derive the densities and the column densities of the cyanopolyynes in these clouds. We derive densities for TMC 1, TMC 2, and L1544 of between 1 and 4 x 10/sup 4/ cm/sup -3/. We have found that the ratios of the cyanopolyynes in these three clouds are the following: HC/sub 3/N/HC/sub 5/Nroughly-equal1.4 and HC/sub 5/N/HC/sub 7/Nroughly-equal3. In L134 N and DR 21(OH) we have measured limits on the HC/sub 5/N emission and find the HC/sub 3/N/HC/sub 5/N ratio to be substantially greater than in the three Taurus clouds. We have also compared the cyanopolyyne column densities with those of /sup 13/CO and find that the abundance of HC/sub 3/N in L134 N and DR 21(OH) is an order of magnitude smaller than that found in the Taurus clouds. The chemical differences between L134 N and the Taurus clouds are particularly interesting in view of their similar physical properties.

• Research Organization: Department of Physics and Astronomy, University of Massachusetts
• OSTI ID: 6294609
• Journal Information: Astrophys. J.; (United States), Journal Name: Astrophys. J.; (United States) Vol. 244:1; ISSN ASJOA
• Country of Publication: United States
• Language: English

Related Subjects

640105* -- Astrophysics & Cosmology-- Galaxies
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABUNDANCE
CHEMICAL COMPOSITION
CHEMISTRY
COSMOCHEMISTRY
CYANIDES
DATA ANALYSIS
ENERGY SPECTRA
ENERGY-LEVEL TRANSITIONS
FUNCTIONS
HYDROCARBONS
INTERSTELLAR SPACE
MATHEMATICAL MODELS
MOLECULES
NEBULAE
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
RADICALS
SPACE
SPECTRA
SPECTRAL DENSITY
SPECTRAL FUNCTIONS
STATISTICAL MODELS