2013 Maxwell medal and prize

Dr Joanna Dunkley, University of Oxford. For her contributions to determining the structure and history of our Universe

As part of NASA’s WMAP satellite Science Team, Joanna Dunkley has played a leading role in the analysis of relic radiation from the Big Bang - the Cosmic Microwave Background. This work included placing state-of-the-art constraints on properties of the universe such as its contents, age, geometry, primordial fluctuations, and neutrino mass, and finding the first cosmological evidence for neutrinos and primordial helium. With the WMAP team she found the most precise estimates of the amount of Dark Energy and Dark Matter in the Universe, and the best characterization of inflation - the rapid expansion of the universe in the first trillionth of a second.

She then led analysis for the Atacama Cosmology Telescope in Chile, observing the CMB at higher resolution. This has generated numerous new results; she led the cosmological analysis in 2010 placing the tightest constraints on the number of neutrino species in the universe, and better constraining inflationary properties. She then used the first detection of gravitational lensing in the CMB from ACT to show new evidence for the presence of Dark Energy in the universe. These results were named one of the year’s highlights in Physics Today.

Extracting cosmological signals from the CMB, involves overcoming contamination from our own Galaxy and from many other distant galaxies. To this end she has made significant contributions to the modelling of the clustering of high redshift galaxies, measured properties of both anomalous dust emission and polarized synchrotron emission in our own Galaxy, and developed novel statistical techniques to extract the tiny primordial signals from the intervening light.