Introductory lecture
Abstract
Observational evidence, theory, and techniques for characterizing extragalactic radio sources are explored. It is noted that radio sources detected at the limits of observational capability are actually providing information of conditions which existed when the universe was different from the present time. Small and massive nuclei are now accepted as significant forces in the formation of radio sources, and may actually be black holes surrounded by accretion disks. However, direct evidence for the existence of black holes is lacking, a deficit which it is hoped the Space Telescope will fill, particularly through confirmation of velocity dispersions around M87, which has been calculated to have a core mass of three billion solar masses. Methods of determining if a black hole also exists at the center of the Galaxy are reviewed. Attention is also given to gases emitted from the centers of galaxies such as NGC 4258, and to nonquasar radio galaxies.
- Publication:
-
Extragalactic Radio Sources
- Pub Date:
- 1982
- Bibcode:
- 1982IAUS...97....1O
- Keywords:
-
- Astronomical Spectroscopy;
- Extragalactic Radio Sources;
- Radio Astronomy;
- Black Holes (Astronomy);
- Brightness Temperature;
- Cosmology;
- Galactic Nuclei;
- Galactic Structure;
- Jet Flow;
- Milky Way Galaxy;
- Radio Galaxies;
- Universe;
- Astrophysics