On satellite lines anomalies in OH excited states.
Abstract
Recent observations of radio emission from excited states of OH in the source G291.3-0.7 indicate an emission pattern arising in the 2pi 3/2 (J=5/2) state that is similar to the familiar pattern in the ground state. It is suggested that these observations are compatible with collisional excitation of the 2pi 3/2 (J=5/2) state and that the pattern follows from the structure of the energy-level diagram and photon-trapping effects rather than from any particular pump. An attempt is made to examine the behavior of the 2pi 3/2 (J=5/2) and 2pi 1/2 (J=1/2) states under radiative and collisional pumping conditions. It is concluded that the emission patterns considered are independent of the pumping process and cannot by themselves indicate what excitation mechanism is in operation.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- April 1977
- DOI:
- 10.1093/mnras/179.2.143
- Bibcode:
- 1977MNRAS.179..143E
- Keywords:
-
- Hydroxyl Emission;
- Infrared Radiation;
- Optical Thickness;
- Radio Emission;
- Electron Transitions;
- Energy Levels;
- Ground State;
- Pumping;
- Astrophysics