A study of the hot galactic halo
Abstract
The galactic halo is regarded as a hot spherical plasma medium. From the plasma equations, dispersion relations are derived for the transverse and associated waves. In general, plasma oscillations will not be damped in the halo, although damping can occur near the center if streams of ionized particles are present. Since plasma-wave damping would be a very effective heat source, the inner part of the halo gradually ought to lose heat, both because damping is absent and by thermal or nonthermal radiation. In this event, according to Spitzer, mass would leave the halo and flow down into the inner part of the Galaxy. This process could replenish the substantial mass loss experienced by the galactic nucleus. Expressions are also obtained for the phase velocity of the plasma waves. For a material plasma wave the phase velocity will exceed the escape velocity, implying that some agent other than gravitation, such as a magnetic field, counteracts the tendency of the ionized gas to escape.
- Publication:
-
Astronomicheskii Zhurnal
- Pub Date:
- August 1978
- Bibcode:
- 1978AZh....55..683S
- Keywords:
-
- Galactic Structure;
- Halos;
- High Temperature Plasmas;
- Interstellar Gas;
- Plasma Dynamics;
- Astronomical Models;
- Energy Dissipation;
- Galactic Evolution;
- Nonthermal Radiation;
- Plasma Waves;
- Astrophysics