Galaxy formation - A historical short review
Abstract
Leading theories on galaxy formation are discussed, and the difficulties and inconsistencies of each are examined. These theories are represented by the following general aproaches: (1) the eastern trend (developed mainly by Russion researchers represented by Zeldovich, 1978), called the top-down theory, the fragmentation theory, the pancake theory, or the adiabatic theory; (2) the western-trend theory (developed mainly by American and British researchers represented mainly by Peebles, 1980), called the bottom-up theory, the hierarchical clustering theory, or the isothermal theory; and (3) the hierarchical explosion hypothesis, introduced by Ostriker and Cowie (1981) and Ikeuchi (1981). While the first two trends are common in utilizing the gravitational force for the formation of galaxy, the hierarchical explosion hypothesis assumes the isothermal perturbation for seeds with the mass of about 10 to the 8th solar masses; this seed collapses to a stellar system, and eventually, massive stars explode as supernovae.
- Publication:
-
Chemical Evolution of Galaxies with Active Star Formation
- Pub Date:
- 1987
- Bibcode:
- 1987cega.proc...19I
- Keywords:
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- Big Bang Cosmology;
- Galactic Evolution;
- Relic Radiation;
- Adiabatic Conditions;
- Isothermal Processes;
- Jeans Theory;
- Astrophysics