The gas distribution in the central region of the Galaxy. I. Atomic hydrogen.
Abstract
A phenomenological model that accounts in a simple and coherent manner for many of the anomalous phenomena observed toward the galactic nucleus is developed. This model for the inner-Galaxy gas distribution invokes rotation and outward flow of comparable magnitude in an inclined thin disk, as well as gas density variation only with distance from the mean plane of the disk and axisymmetric velocity fields. The model is used to generate synthetic H I profiles for comparison with observations. Moment maps of integrated H I intensity as they appear projected onto the plane of the sky are examined along with intensity contours in an (l, v) map constructed along the major axis of the fundamental gas distribution, the observed and predicted behavior in 10 representative (l, v) maps, and the same behavior in four (b, v) maps. It is shown that the appearance of apparently isolated and anomalous spectral features is a consequence of transforming the properties of the tilted disk into the observed coordinates and intensities
- Publication:
-
The Astrophysical Journal
- Pub Date:
- November 1978
- DOI:
- 10.1086/156547
- Bibcode:
- 1978ApJ...225..815B
- Keywords:
-
- Astronomical Models;
- Density Distribution;
- Galactic Nuclei;
- Galactic Structure;
- Gas Density;
- Interstellar Gas;
- Milky Way Galaxy;
- Cosmic Gases;
- Disks (Shapes);
- Emission Spectra;
- Galactic Rotation;
- Hydrogen Atoms;
- Hydrogen Clouds;
- Astrophysics;
- Galactic Center:Neutral Hydrogen;
- Galactic Structure;
- Galaxy:Internal Motions;
- Galaxy: 21 cm Radiation