Galaxies are the visible fabric of the Universe. These luminous cities of stars can be seen across great distances in the Universe and, because the speed of light is finite, they provide astronomers with the remarkable opportunity to witness their birth and evolution. By using large ground and space-based telescopes, detailed information has been gathered on the properties of galaxies back to a time when the Universe was barely 5% of its present age. The challenge lies in connecting these `time-slices’ of cosmic history into a physical picture of galactic evolution. A detailed understanding of the development of galaxies enriches our view of the evolving Universe and I will describe the progress being made.
Richard Ellis is the Steele Professor of Astronomy at the California Institute of Technology in Pasadena. A Welshman by birth, he was an undergraduate at University College London and gained his Ph.D. at Oxford. He became a professor of astronomy at the University of Durham in 1985. He was appointed the Plumian Professor at Cambridge in 1993 and served as Director of the Institute of Astronomy from 1994 to 1999. He has published widely on topics in observational cosmology and galaxy evolution and has recently charted the earliest period of cosmic history, when the first galaxies emerged. Within both the UK and USA he has led discussions for new observational facilities, the most recent example being the Thirty Meter Telescope now under construction atop Mauna Kea on the island of Hawaii. Ellis is a Fellow of the Royal Society and was awarded the Gruber Cosmology Prize for his part in the discovery of the accelerating Universe, and the Royal Astronomical Society’s Gold Medal.