Preface

Acknowledgements

A large number of people have helped in various ways in the construction of this thesis. They include people who have provided both scientific and non-scientific help, support and advice, all of which have helped this production. I wish to thank first and foremost my supervisor, Lawrence Cram, and my wife, Toni Hopkins. They have both played a major role in making this thesis what it is, and I want to let them know how much their presence and efforts are appreciated.

I wish to thank Bahram Mobasher for extensive collaboration and the input of ideas and methods, and for hosting me at Imperial College for a time. My thanks go also to Rogier Windhorst for his help and advice, and for his approachability and hospitality.

I want to thank all the staff and students of the Astrophysics Department for continual support and camaraderie during the last four years. Students from other departments and institutions, too, also have my thanks in this area. In particular I want to give my thanks to Julia Bryant, Tanya Hill, Eileen O'Hely, Andrew Reid, Bryan Gaensler and Gene Davidson, for innumerable quantities of help and fun. Tom McDermott has my thanks for his incredibly helpful efforts in getting the radio images printed.

Others whose efforts deserved to be mentioned include Chris Pearson and Antonis Georgakakis from Imperial College, Chris Lidman from ESO, and all of the staff of the ATCA and of the AAT, in particular Bob Sault, Neil Killeen and Jeremy Bailey.

To all of you, Thank You.

The Australia Telescope is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. This research has used the NASA/IPAC Extragalactic Database (NED) which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration. The research has also used the NRAO VLA Sky Survey (NVSS) Database. The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.

Statement of Originality

This thesis describes work carried out in the Department of Astrophysics at the University of Sydney between 1994 and 1997. The sections of Chapters 2 and 3 relating to the radio observations, data reduction and source count analysis are the subject of a paper accepted for publication by Monthly Notices of the Royal Astronomical Society, on which I am first author. Except where acknowledged otherwise, the work presented in this thesis is my own. The major contributions from other people are as follows:

• Lawrence Cram performed the analysis described in Chapter 7,
• Antonis Georgakakis carried out the data reduction of the K-band data from IRAC2b,
• Chris Lidman performed the data reduction of the EFOSC spectral data.

Astronomical Units

For consistency with much of the published work in astronomy, the following non-SI units are used in this thesis:

• The Jansky (Jy):
  

  $$1\,{\rm Jy} = 10^{-26}\,{\rm W\,Hz}^{-1}\,{\rm m}^{-2}$$ (1)

  
  

• The Parsec (pc):
  

  $$1\,{\rm pc} = 3.086\times10^{16}\,{\rm m}$$ (2)

  
  

• The Solar Mass (M$_{\odot}$):
  

  $$1\,{\rm M}_{\odot} = 1.989\times10^{30}\,{\rm kg}$$ (3)

  
  

Throughout this thesis the value of the Hubble constant, H₀, is taken to be 50 kms^-1Mpc^-1, and the deceleration parameter q₀=0.5. All logarithms in this thesis are base 10 unless indicated by use of the natural logarithm symbol, "$\ln$", or otherwise specified.