Image credits, left to right: [1] Art: Measuring mistakes by Ulrike Kuchner. Lapel pin: CepheidStudio. [2] EROJ003707+0909.5, aka the space-invader. [3] Mapping dark matter with gravitational lensing. [4] Searching for gravitationally lensed gravitational waves.
Research: exploring the universe through gravitational lenses
I use gravitational lensing to explore big questions about how the universe works, including the nature of dark matter and dark energy, and the formation of compact objects and galaxies through cosmic time. I currently focus on multi-messenger gravitational lensing, including pioneering searches for electromagnetic counterparts to gravitationally lensed gravitational waves, and enabling exciting discoveries with Rubin's Legacy Survey of Space and Time.
As a Royal Society University Research Fellow (2005-2014), I created and led the Local Cluster Substructure Survey (LoCuSS), a collaboration of 30 colleagues from a dozen countries. We used gravitational lensing to calibrate galaxy clusters as a cosmological probe and constrain the physics of galaxy transformation in clusters. Our unique dataset included data from Chandra, XMM-Newton, GALEX, HST, Keck, Subaru, Gemini, UKIRT, Spitzer, Herschel, and CARMA. Many of our key results were led by students and postdocs.
As a Postdoc at Caltech (2002-2005) I lead the first measurement of the galaxy morphology-density relation at high redshift, and pioneered gravitational lensing as a tool for measuring the relationships between the mass of galaxy clusters and their observable properties. Today these relationships are central to galaxy clusters as a probe of dark energy. I received the Royal Astronomical Society's Fowler Award for this work in 2007.
As a PhD student at Durham University (1999-2002) I was among the first to use radial arcs to explore the nature of dark matter, and combined near-infrared observations with gravitational lensing to test theories of galaxy formation. I also discovered the gravitationally lensed galaxy that was later re-christened the space invader.
I acknowledge funding in recent years from The Royal Society, the Leverhulme Trust, the Science and Technology Facilities Council, and the Royal Astronomical Society.
