Astrophysics and Planetary Science at Oxford 2013-16

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The Cosmic Microwave Background (CMB) is a cornerstone of cosmology and its precise measurement is of the highest importance but it is heavily polluted by emission from our Galaxy. We propose a new measurement of that foreground radiation at low frequencies which will lead to a more precise interpretation of the data from the Planck satellite. Combining insights from this work with results from other CMB telescopes will lead to a better understanding of the inflationary epoch and dark Universe. To probe the distribution of dark matter we have developed state of the art techniques for the measurement and interpretation of the minute distortions of the images of distant galaxies that arise from matter along the line of sight. This work exploits current surveys but is looking towards future involvement in ESAs EUCLID satellite. We are actively pursuing complementary approaches to measuring the structure of the Universe and the parameters that describe it. From time-domain surveys we will discover distant supernovae and strive for a better understanding supernova physics. The imprint of the large scale structure is revealed through the distribution of galaxies, and we are measuring this over a range of epochs to track how the structure evolves.Supernovae and active galactic nuclei regulate star formation and deposit huge amounts of energy into interstellar gas. We will observe directly galaxies less than one billion years after the Big Bang to see when they formed their first stars and the effect they have on their surroundings. We can even probe the CO gas in and around galaxies at these early epochs. We will model these complex processes in a cosmological setting using advanced techniques of high performance computing. We will use the same techniques to study the origin of magnetic fields and the acceleration of cosmic rays in supernova remnants. We are proposing to utilise our citizen science infrastructure to characterise galaxies from the HST CANDELS survey and search for the causes of activity in galaxies. New instruments will enable us to apply the diagnostics we developed for local galaxies to galaxies seen when the Universe was half its present age. By studying galaxies in both the densest clusters and in the most rapidly star-forming dusty galaxies we will explore the dependence of galaxy evolution on mass and the local neighbourhood. Our Galaxy should place some of the strongest constraints on cosmology, but all observations of it are strongly biased by our position within it. We will map the three-dimensional distribution of extinction in the Galaxy and develop new dynamical models of our Galaxy. Presently our models are constrained by data from ground-based surveys but our work will be used to interpret data from ESA's Gaia satellite.Astronomers have discovered several hundred planetary systems. One technique searches for extremely small but regular dips in brightness that indicate the presence of a planet occulting light from a star. By developing advanced analysis techniques we propose to use these `transits' not only to discover new planets - including ones resembling the Earth - but also to study the structure and composition of their atmospheres. By undertaking careful modelling of the passage of radiation through planetary atmospheres we will rigorously test the validity of such conclusions and assist in the design of future experiments. The atmospheres of the giant planets in the Solar System exhibit surface features, banding and cyclonic spots of unknown origin, furthermore the difference between the gas giants and the ice giants remains to be understood. We intend to apply modelling using high performance computing to the results from planetary missions to investigate the physical mechanisms that underpin these phenomena. Finally we seek to understand the surface composition of the closest astronomical object, the Moon, through comparative spectroscopy and modelling.