The work reported in this thesis falls conveniently into two parts. The first two chapters deal with interstellar while the final two chapters deal with intergalactic material. The problem of the formation of molecules (principally H2) at the surfaces of interstellar dust grains is considered in Chapter I. It is shown that the amounts of formed are sufficient to maintain the interstellar gas at 100°K. The results obtained for CH, CH show that the mechanism considered does not lead to absurd results under the conditions assumed. The importance of at high densities is also discussed. Chapter II deals with a theory of star formation in a medium composed of randomly moving cloudlets or floccules. An outline is given of a recent paper by McCrea who shows that this idea leads to a satisfactory account of the formation of the solar system and removes the angular momentum difficulty of other star formation theories. The collisions of floccules are considered in detail and a theory of the gravitational capture of the fragments of collision is outlined. The expansion of a fully ionised gas into avacuum is discussed in Chapter III. This problem is connected with a recent theory of galaxy formation. The expansion of a monatomic gas and Lagrange's Ballistic problem are first considered. The latter leads to a new model for a freely expanding gas. It is then shown that, if the fully ionised gas remains neutral, by suitably defining the sound speed the equations for a fully ionised gas may be reduced to those for a monatomic gas. Finally in Chapter IV, Hoyle's theory of the origin of the angular velocities of galaxies is reviewed. A specific model based on this theory is discussed. It is shorn that some features of galaxy rotation may be accounted for in terms of this theory.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:703850 |
| Date | January 1961 |
| Creators | McNally, Derek |
| Publisher | Royal Holloway, University of London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://repository.royalholloway.ac.uk/items/75fe733a-bbe3-4a93-a77a-068eeb4f08b2/1/ |
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