Galaxy formation : a personal view
Abstract
This book presents a personal view of galaxy formation in the expanding universe. General properties of the sun, other stars, and galaxies are briefly reviewed, the discovery that extragalactic nebulae are actually external galaxies is recountered, and the concept of an expanding universe is discussed. The following theories of galaxy formation are critically evaluated: formation from turbulent clouds of gas, gravitational instability, Layzer's (1963) gravitational-clustering hypothesis, Ambartsumian's (1958) fragmentation hypothesis, continual creation in a steady-state universe, Jeans' criterion in a Newtonian context, and the retarded-core hypothesis. The growth of irregularities in an expanding universe is examined, and a scenario for galaxy evolution is outlined which involves a sequence from QSOs through N and Seyfert galaxies to ordinary quiet galaxies. It is concluded that there is already enough observational and theoretical evidence to show that galaxy formation is a process related to the presence of singularities and energetic outbursts rather than to the collapse of great clouds of gas.
- Publication:
-
London: MacMillan
- Pub Date:
- 1976
- Bibcode:
- 1976gfpv.book.....G
- Keywords:
-
- Astrophysics;
- Cosmology;
- Galactic Evolution;
- Universe;
- Gas Density;
- Gravitational Collapse;
- Gravitational Effects;
- Jeans Theory;
- Mass Distribution;
- Milky Way Galaxy;
- Quasars;
- Seyfert Galaxies;
- Steady State;
- Stellar Evolution;
- Astrophysics;
- GALAXY FORMATION;
- EXPANDING UNIVERSE;
- COSMOLOGY;
- INTRODUCTIONS;
- GALAXIES: FORMATION