Detection of interstellar OH in the far-infrared
Abstract
Strong absorption lines of OH have been detected at wavelengths of 119.23 and 119.44 microns in the direction of Sgr B2. The lines arise from the 2Pi3/2, J = 5/2-3/2 transitions and imply a column density of N(OH) not less than 2.7 x 10 to the 15th/sq cm. The LSR Doppler velocity of the absorption features is close to zero; this suggests that material is being seen from both the +62 km/s and -90 km/s clouds at radio wavelengths. In addition, the detection of the same two lines in emission from the shocked region of the Orion Nebula has been made possible. The indicated intensity of these lines is 1.6 x 10 to the -17th W/sq cm, which implies a column density of shocked OH of about 3.6 x 10 to the 15th/sq cm.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- February 1981
- DOI:
- 10.1086/183472
- Bibcode:
- 1981ApJ...244L..27S
- Keywords:
-
- Far Infrared Radiation;
- Hydroxyl Emission;
- Hydroxyl Radicals;
- Infrared Astronomy;
- Interstellar Matter;
- Molecular Clouds;
- Absorption Spectra;
- Energy Levels;
- Astrophysics