Durham Astronomy Consolidated Grant 2017-2020

Astronomy attracts the imagination of the public to an extent that only very few other branches of science can match - this is due, in large part, to the fundamental nature of the questions it addresses: the origin of the Universe and our place within it. Astronomy is immediately accessible to every human by simply gazing up into the night sky to look the Moon, the planets and stars. Since the dawn of civilisation this has provoked questions about the origins of the Earth, stars and our Solar System, as well as the origins of the Universe. Over the past thirty years we have seen the emergence of a standard model in cosmology describing the constituents of our Universe, as well as a plausible explanation for the origin and evolution of all structure within it. According to this model, we live in a universe where at least two thirds of all mass-energy is now in the form of a dark energy field which is causing the Universe to expand at an ever increasing rate. About a quarter of the mass-energy is in the form of dark matter, most probably a new weakly interacting elementary particle yet to be detected on Earth (and hence of great interest to particle physicists). Only the remaining five percent of the mass-energy is in the form of ordinary, or baryonic, matter of which, at the present-day, only about a tenth is in stars and planets such as the Earth, and the rest resides mostly as gas in between galaxies. The structures formed by dark and baryonic matter are thought to have been seeded by quantum fluctuations imprinted in the density field of the Universe at the earliest instants of the Big Bang. These produced weak sound waves in the near-uniform primordial plasma that left observable imprints on the heat left over from the Big Bang, emitted when the Universe was only 400,000 years old (now visible as the Cosmic Microwave Background). These tiny ripples grew into the full richness of structures we see around us in the Universe today: galaxies, groups, clusters and larger-scale structures. It is this transformation from a near-uniform primordial soup to a cosmic web of structure that is the focus of our proposal. Our programme knits together cutting-edge theoretical research into the earliest phases of the Universe with theoretical and observational projects to determine the formation and evolution of structure in the Universe and to confront the predictions of our models with our latest observational results, while exploiting instrumentation developments pursued in Durham. We will explore astrophysical clues to the identity of the dark matter and the nature of the dark energy, focus on the evolution of galaxies back to the earliest times in the Universe and the influence which their environment has had on their properties. We will investigate the formation and evolution of black holes and their role in determining the structure and properties of galaxies and larger scale structures, using the latest instruments on ground-based observatories and Earth-orbiting satellites.