X-ray emission from clusters of galaxies.

Clusters of galaxies are the largest gravitationally bound systems known. The study of clusters can therefore provide information on the distribution of matter in the Universe on the largest scales. The X-ray emission from clusters is of particular interest, as the gas held within the gravitational potential well of a cluster responds to the total mass ('Dark' and 'Visible') of that cluster. This thesis is based upon a sample of 44 observations of clusters made by EXOSAT which provided both imaging and spectral data. The data give well determined luminosities, temperatures, iron abundances and mass flow rates for these clusters. The results provide constraints on models for cluster dynamics and formation. The theoretical models and previous observations of clusters are reviewed in Chapter 1, concentrating on the X-ray domain. The results from the imaging telescopes and proportional counters are given in Chapters 2 and 3. Detailed observations of Virgo, Coma and Perseus are described in Chapter 4. A correlation analysis of the X-ray, optical and radio results is presented in Chapter 5. The implications of these correlations are discussed in Chapter 6. The thesis concludes with a brief look forward to future missions.