Gas temperature and motion in the Taurus dark cloud.
Abstract
Second-order magnetic hyperfine structures of the J, K = 1, 1 transition of NH3 have been resolved toward Taurus and other dark clouds. A line width of 0.27 km/s is deduced for each hyperfine component toward Taurus. This corresponds to a kinetic temperature of approximately 28 K if the observed line width is taken to be thermal. From the excitation temperature of (C-12)O and an upper limit on the J, K = 2, 2 line of NH3, the kinetic temperature is deduced to be about 12 K. Line broadening in NH3, CO, OH, and H I is attributed to large-scale motion. This is consistent with an observed velocity gradient of 2 km/s per pc across the line of sight.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- July 1977
- DOI:
- 10.1086/182470
- Bibcode:
- 1977ApJ...215L..29H
- Keywords:
-
- Ammonia;
- Gas Temperature;
- Hyperfine Structure;
- Interstellar Gas;
- Molecular Spectra;
- Astronomical Spectroscopy;
- Carbon Monoxide;
- Gas Flow;
- Hydrogen;
- Hydroxyl Emission;
- Spectral Line Width;
- Astrophysics