Ammonia in Orion. III. The gas in and around OMC-1.
Abstract
Results of ammonia observations of the Orion region made with an angular resolution of 40 arcsec are presented. The spike velocity component appears to be extended relative to the beam, and nonlinear least squares fits spectra taken with long integrations on the peak of BN/KL yield a rotational temperature of about 40 K. The NH3 column densities are combined with (N-15)H3 data of Wilson and Pauls (1979) to obtain a (N-14)H3/(N-15)H3 ratio of 480 + or - 150. The rotational temperature of the plateau velocity component is about 30 K, and the velocity component at 5.5 km/s is optically thick in the (1,1) (2,2) (3,3), and (4,4) lines from nonlinear least squares fits to the hyperfine components. Detections of the (8,8) and (9,9) lines indicate that only the velocity component at 5.5 km/s is present in lines found at greater than 500 K above the ground state, and a rotational temperature of 150 + 30 or - 10 K is obtained.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- December 1981
- Bibcode:
- 1981A&A...104..288Z
- Keywords:
-
- Ammonia;
- Line Spectra;
- Molecular Clouds;
- Molecular Spectra;
- Orion Nebula;
- Angular Resolution;
- Brightness Temperature;
- Curve Fitting;
- Fine Structure;
- Gas Temperature;
- Infrared Radiation;
- Radial Velocity;
- Spectral Line Width;
- Astrophysics