L'hydrogène neutre interstellaire
Abstract
Current knowledge of neutral hydrogen in the interstellar medium, obtained by radioastronomical techniques, is reviewed. The interstellar environment is considered, with attention given to the temperatures and densities of H I regions, the intercloud medium, coronal gas, compact molecular clouds and H II regions surrounding early stars. Astronomical observation techniques are presented, emphasizing radio methods for the observation of the 21-cm line of neutral hydrogen. Results of observations of 21-cm emission and absorption are discussed, noting the data obtained on the structure of the Galaxy and the distribution of H clouds. The continuity of density between diffuse and molecular clouds is also noted.
- Publication:
-
L'Astronomie
- Pub Date:
- August 1979
- Bibcode:
- 1979LAstr..93..317C
- Keywords:
-
- Interstellar Gas;
- Neutral Gases;
- Radio Astronomy;
- Absorption Spectra;
- Gas Temperature;
- Graphs (Charts);
- H I Regions;
- H Ii Regions;
- Hydrogen Atoms;
- Hydrogen Ions;
- Milky Way Galaxy;
- Astrophysics