Formaldehyde in the Galactic Center region: interpretation.
Abstract
The molecular clouds within 300 pc of the galactic center are discussed on the basis of the results of the recent, fully sampled survey by Bieging et al. (1980) of formaldehyde absorption at 4.8 GHz. Consideration is given to the stability against tidal forces and relative locations of the individual clouds at galactic longitudes within 0.2 deg of the center, including the two molecular clouds seen toward Sgr A, the Bridge between Sgr A and Sgr B2, the 25 km/sec cloud at l equals 0.25 deg and b equals 0.0 deg and the forbidden features at -30 km/sec and -75 km/sec near l equals 0.2 deg. Molecular clouds in the vicinity of the continuum arc or spur near l equals 0.2 deg are considered, and the large-scale nuclear disk and the molecular ring are discussed, with particular attention given to the possible inclination of the disk and the origin of ring expansion. It is suggested that all of the massive clouds within longitudes of 1 deg from the center are at galactocentric radii greater than 100 pc due to the gravitational forces of the central stellar distribution.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- July 1980
- Bibcode:
- 1980A&A....87....6G
- Keywords:
-
- Formaldehyde;
- Galactic Nuclei;
- Galactic Structure;
- Interstellar Gas;
- Line Spectra;
- Molecular Gases;
- Astronomical Maps;
- H Alpha Line;
- Optical Thickness;
- Ring Structures;
- Star Distribution;
- Stellar Evolution;
- Astrophysics