The hydrocarbon ring C3H2 is ubiquitous in the galaxy.
Abstract
The discovery of a strong microwave (1.6 cm-wavelength) spectral line, the carrier of which is common and widespread throughout the Galaxy is reported. A survey of a large number of sources shows that the line appears in emission in cold dust clouds, in absorption in the direction of the Galactic center, and exhibits complex profiles toward H II regions. Toward Cas A and distant H II regions, intervening 'spiral arm' clouds produce absorption. For almost all cases, the absorption features show a striking 1:1 radial velocity correspondence with those seen, e.g., in H2CO spectra of the same objects. The data indicate that the line arises between low-lying energy states of a rather polar molecule. Recent work by Thaddeus, Vrtilek, and Gottlieb (1985) incorporating the present data, shows that the line in question is the 1(10)-1(01) transition of the small hydrocarbon ring C3H2.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1985
- DOI:
- 10.1086/184567
- Bibcode:
- 1985ApJ...298L..61M
- Keywords:
-
- Cyclic Hydrocarbons;
- Galactic Structure;
- Interstellar Matter;
- Milky Way Galaxy;
- H Ii Regions;
- Line Spectra;
- Molecular Structure;
- Ring Structures;
- Stellar Envelopes;
- Astrophysics