Annu. Rev. Astron. Astrophys. 1984. 22: 185-222 Copyright © 1984 by Annual Reviews. All rights reserved

4. THE EVOLUTION OF DIFFERENT MORPHOLOGICAL TYPES

The previous section reviewed the major processes that can alter the mass functions and spatial distributions of galaxies in regions of high galaxy density. In this section, the level of complexity is raised to include the forms of the luminous matter, described by the morphological type of the galaxy. This requires additional knowledge of how the processes described above, combined with initial conditions, will vary the density, angular momentum, and gas content in a way that produces the observed range and distribution of morphological types. Again, clusters are ideal laboratories in which to study these effects, since they contain a different mix of galaxy types than is seen in the low-density field.