OH Zeeman Observations of Dark Clouds
Abstract
Measurements with the Green Bank 43-m telescope of the Zeeman effect in the 1665- and 1667-MHz lines of OH toward dark clouds are reported. The typical 1-sigma sensitivity was 3 micro-G. The total field strength was found to be typically about 16 micro-G toward the central regions of dark clouds sampled by the Green Bank beam, from which it is implied that the central regions were approximately magnetically critical. The data were found to be consistent with the hypothesis that dark clouds are in approximate virial equilibrium between magnetic and gravitational energy and that the supersonic line widths observed in dark clouds are the result of MHD motions such as Alfven waves.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1993
- DOI:
- 10.1086/172503
- Bibcode:
- 1993ApJ...407..175C
- Keywords:
-
- Dark Matter;
- Hydroxyl Radicals;
- Interstellar Magnetic Fields;
- Zeeman Effect;
- Astronomical Models;
- Spectral Line Width;
- Astrophysics;
- ISM: CLOUDS;
- ISM: MAGNETIC FIELDS;
- ISM: MOLECULES