Professor of Astrophysics
I have been in the astrophysics group of the Oxford Physics department since 1996. My research currently comprises two main strands. In observational cosmology, I am interested in measuring and understanding the large scale structure of the Universe, trying to understand the nature of dark matter and dark energy. In the study of active galaxies, I am interested in the cosmic evolution of black hole accretion and in the astrophysical processes at the heart of accretion onto supermassive black holes at the centres of galaxies, using X-ray observations to probe the black hole environment.
My cosmology work largely centres around surveys to measure the effect of weak gravitational lensing from deep, large-area galaxy surveys. I am particularly interested in the challenging statistical problem of making high accuracy weak lensing measurements that are free of systematic error to a sufficient level to enable an accurate understanding of large-scale structure in the Universe.
I have worked on the recent CFHTLenS, CS82 and RCSLenS weak lensing surveys, and am actively working on the KiDS survey. But a significant part of my work is the development of the analysis systems needed to measure weak lensing in the European Space Agency's Euclid mission and in the ground-based LSST optical survey and SKA radio survey.
My Euclid development work is funded by the U.K. Space Agency.