This award will provide support for a broad program of observations to be made with the Palomar and Keck telescopes in order to use the absorption lines in the spectra of quasars to study the evolution of intergalactic clouds and the interstellar gas in galaxies from their origin to the present epoch. Very high resolution spectra will be obtained of a sample of very distant quasars in order to make detailed studies of the absorption spectra produced by the light from these quasars passing through intervening galaxies and intergalactic clouds. The results from these studies will be used to study the physical nature of these clouds. The Principal Investigator is regarded as a world authority on this subject.
