Astronomy and Astrophysics at Edinburgh

This grant supports research in astronomy and astrophysics in Edinburgh, which spans processes from cosmological scales of billions of light years, down to the creation of stars, and the formation and evolution of planets and planetary systems. Our research involves observation, theory and numerical simulation, and in particular brings these different aspects together to address some of the most fundamental questions that humans have asked since the dawn of civilisation: what are the origins of the Earth and the objects that we see in the sky at night, and what is our place in the Universe? Remarkable progress in our understanding has been made over the last few decades. On the largest scales, a standard model for cosmology has emerged, which can explain the expansion history of the Universe and the distribution of matter within it. In this model, only five percent of the Universe is composed of normal 'baryonic' matter - the matter we are familiar with, from which planets and stars are made. The rest is composed of exotic material known as 'dark matter', and a 'dark energy' field which is causing the rate of expansion of the Universe to increase. However, the nature of dark matter and dark energy remain unknown. Our proposed research addresses this, by studying their effects on the large-scale distribution of galaxies, the distortions that they cause to the light reaching us from distant galaxies (a process known as gravitational lensing), and more locally their effect on the distributions and orbits of stars and star clusters in our own and nearby galaxies. Detailed observations of large samples of galaxies across cosmic time, combined with precision studies of the Milky Way and nearby galaxies, have led to an enhanced understanding of how galaxies form and evolve. Cosmological simulations are able to provide a remarkable match to observations and are providing considerable insight into the physical processes that must be driving galaxy evolution. Nevertheless, we still lack a complete understanding of what regulates star formation in galaxies, and how massive black holes (a million to a billion solar masses) and active galactic nuclei (AGN) form at their centres. Modern theory favours an input of energy from supernovae and AGN to heat and expel gas out of galaxies, but the details are not fully understood. Our research addresses this, through detailed studies of the galaxy population across cosmic time, the black holes within them, and the impact of galaxies and AGN on their gaseous surroundings. On much smaller scales, it is only just over two decades since the first planet outside our Solar System was detected; more than 4000 of these exoplanets are now known. The remarkable diversity of the population of detected exoplanets, compared to the planets in our own Solar System, is revolutionising our understanding of how planetary systems form, but also opening up many new questions. Our research focusses primarily on simulations of planet formation, and on direct imaging and spectroscopic studies of exoplanets to understand their atmospheres and nature. Our research in Edinburgh is driven by technological breakthroughs in observational facilities and computing power, and enhanced by novel statistical analysis techniques and new theoretical approaches. During the period of this grant, Edinburgh researchers will lead major new surveys and high-precision measurements at wavelengths across the electromagnetic spectrum from X-rays to radio waves, using ground-based observatories and space-based satellites. Our sophisticated new simulations will provide detailed predictions, to be compared to current and ongoing observational data. We anticipate major progress in our understanding of the full history and structure of our Universe and our place within it.