西佛星系
His research interests include active galactic nuclei (particularly Seyfert galaxy, Radio galaxy and quasars) and the ways in which large galaxies and their central supermassive black holes have changed and evolved throughout cosmological time. This research has involved the use of a variety of telescopes, including the Hubble Space Telescope, the Very Large Array, MERLIN, the William Herschel Telescope, and the Very Large Telescope.