About Professor Geraint F. Lewis

The Universe is a complex and dynamic place, and my research focuses on understanding how it ticks.

Geraint F. Lewis is a Professor of Astrophysics at the Sydney Institute for Astronomy, researching cosmology, gravitational lensing and galactic cannibalism.

Geraint F. Lewis heads the Gravitational Astrophysics Group at the Sydney Institute for Astronomy, whose research covers several key areas in modern astrophysics, including deciphering the nature of the dark matter and dark energy which pervade our Universe, and understanding the evolution of galaxies out of the cosmic broth that existed shortly after the Big Bang. For this, the Gravitational Astrophysics Group use state-of-the-art computational facilities to build model universes, modifying the underlying physics and unraveling its observational consequences. This can involve following baby galaxies to maturity, or seeing how the structure of matter can influence the paths of light rays as they traverse the Universe.

Geraint’s research is augmented with an ongoing study with some of the world’s largest and keenest telescopes to observe our own Galactic neighbourhood, uncovering the formation history of galaxies within our Local Group by identifying the tell-tale signature of ancient accretion events. These occur when one galaxy strays to close and is consumed by another, an act of galactic cannibalism, and have revealed the epoch of galaxy formation is not over, and our own Milky Way continues to grow.

Geraint completed his first degree in Physics and Astronomy at the University of London in 1990, followed a PhD at the University of Cambridge’s Institute of Astronomy. He was subsequently a post-doctoral researcher in the USA and Canada, before joining the Anglo-Australian Observatory in 2000. Coming to the University of Sydney in 2002, Geraint has played an active and successful role in the supervision of both undergraduate and graduate students in research projects.

Visit the Gravitational Astrophysics Group at http://www.physics.usyd.edu.au/GravAst


Selected publications

"Can early dark energy be detected in non-linear structure?", Francis, Matthew J., Lewis, Geraint F., & Linder, Eric V.,  (2009), Monthly Notices of the Royal Astronomical Society,  394,  605

"Cosmological radar ranging in an expanding universe", Lewis, Geraint F., Francis, Matthew J., Barnes, Luke A., Kwan, Juliana, & James, J. Berian,  (2008), Monthly Notices of the Royal Astronomical Society,  388,  960

"The Haunted Halos of Andromeda and Triangulum: A Panorama of Galaxy Formation in Action", Ibata, R., Martin, N. F., Irwin, M., Chapman, S., Ferguson, A. M. N., Lewis, G. F., & McConnachie, A. W.,  (2007), Astrophysical Journal,  671,  1591

"Modeling the Evolution of Infrared Luminous Galaxies: The Influence of the Luminosity-Temperature Distribution", Lewis, G. F., Chapman, S. C., & Helou, G.,  (2005), Astrophysical Journal,  621,  32

"A Molecular Einstein Ring: Imaging a Starburst Disk Surrounding a Quasi-Stellar Object", Carilli, C. L., Lewis, G. F., Djorgovski, S. G., Mahabal, A., Cox, P., Bertoldi, F., & Omont, A.,  (2003), Science,  300,  773

"Spatially resolved STIS spectra of the gravitationally lensed broad absorption line quasar APM08279+5255: the nature of component C and evidence for microlensing", Lewis, Geraint F., Ibata, Rodrigo A., Ellison, Sara L., Aracil, Bastien, Petitjean, Patrick, Pettini, Max, & Srianand, Raghunathan,  (2002), Monthly Notices of the Royal Astronomical Society,  334,  L7

"A giant stream of metal-rich stars in the halo of the galaxy M31", Ibata, Rodrigo, Irwin, Michael, Lewis, Geraint, Ferguson, Annette M. N., & Tanvir, Nial,  (2001), Nature,  412,  49

"Great Circle Tidal Streams: Evidence for a Nearly Spherical Massive Dark Halo around the Milky Way", Ibata, Rodrigo, Lewis, Geraint F., Irwin, Michael, Totten, Edward, & Quinn, Thomas,  (2001), Astrophysical Journal,  551,  294

"The Effects of Gasdynamics, Cooling, Star Formation, and Numerical Resolution in Simulations of Cluster Formation", Lewis, Geraint F., Babul, Arif, Katz, Neal, Quinn, Thomas, Hernquist, Lars, & Weinberg, David H.,  (2000), Astrophysical Journal,  536,  623

"Submillimeter Observations of the Ultraluminous Broad Absorption Line Quasar APM 08279+5255", Lewis, Geraint F., Chapman, Scott C., Ibata, Rodrigo A., Irwin, Michael J., & Totten, Edward J.,  (1998), Astrophysical Journal,  505,  L1