Neutral hydrogen in the galactic centre region. - III. Absorption measurements.
Abstract
Hydrogen-line absorption measurements of the continuum sources G 357.7-0.1, G 359.4-0.1 Sgr A, G 0.5+0.0, Sgr B2, and G 1.1-0.1 are presented. The observations have an angular resolution of 13 x 13 arcmin and a velocity resolution of 7.3 km/s. Four of the sources show definite absorption from the molecular-ring feature, placing them at or beyond the galactic center. The neutral hydrogen (H I) data are compared with OH and CH2O absorption data. Within the absorbing clouds the OH/H I abundance ratio is found to increase towards the galactic center according to an exponential law. This is in reasonable agreement with the mass distribution of the galactic disk derived by Innanen (1966). The CH2O/H I abundance ratio is found to follow a similar law.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- March 1977
- DOI:
- 10.1093/mnras/178.4.547
- Bibcode:
- 1977MNRAS.178..547C
- Keywords:
-
- Absorption Spectra;
- Galactic Nuclei;
- H Lines;
- Hydrogen Clouds;
- Neutral Particles;
- Abundance;
- Astronomical Spectroscopy;
- Hydrogen Atoms;
- Mass Distribution;
- Astrophysics