Radio radiation from interstellar molecules.
Abstract
Over 20 radio molecules, composed of as many as seven atoms have been observed. Questions concerning the detectability of radio frequency transitions of a molecule in interstellar space are considered along with estimates of molecular projected densities, envelopes around far infrared sources and H II regions, and protostellar and stellar sources. Optically dark nebulae are examined, taking into account densities, temperatures, the anomalous absorption by H2CO, and dark clouds projected on distant continuum sources. Molecular clouds associated with far infrared sources and H II regions are discussed together with the galactic center, aspects of galactic structure, isotopic abundances, and the isotropic background radiation.
- Publication:
-
Annual Review of Astronomy and Astrophysics
- Pub Date:
- 1974
- DOI:
- 10.1146/annurev.aa.12.090174.001431
- Bibcode:
- 1974ARA&A..12..279Z
- Keywords:
-
- Interstellar Matter;
- Maser Outputs;
- Molecular Energy Levels;
- Radio Emission;
- Background Radiation;
- Brightness Temperature;
- Electron Transitions;
- Far Infrared Radiation;
- Galactic Structure;
- H Ii Regions;
- Hydroxyl Emission;
- Line Spectra;
- Nebulae;
- Optical Thickness;
- Stellar Evolution;
- Astrophysics