C Knigge - Astrophysics at Southampton

All aspects of our research programme are related to the physics of compact objects: the supernova explosions that create and destroy them, the accretion processes that make them luminous X-ray sources, the outflows that appear to accompany all disk-accreting systems, and the effect they have on their environment. Our goals are both to understand the physics behind these phenomena and to exploit them, especially for cosmological purposes. We have a particular interest in time-domain astrophysics as an efficient tool for pursuing these goals. These research interests cover a huge range of scales, from accreting white dwarfs, neutron stars and stellar-mass black holes, to quasars and active galactic nuclei (AGN). In this application, we request support for projects across the range of topics outlined above. On Galactic (i.e. stellar) scales, we will use simultaneous fast X-ray, UV and optical observations to shed new light on the variability of accreting X-ray binaries. We will also produce the most sensitive time-domain hard X-ray ``meta-survey'', by synthesizing data from three separate space missions for the first time. On extra-galactic scales, we will self-consistently model the observational signatures of accretion disk winds in AGN and thus test outflow-based unification scenarios. We will also use multi-wavelength time-domain observations of AGN to understand the disk geometry and emission processes close to the supermassive black hole. Additionally, we will leverage a NuSTAR X-ray legacy survey we are leading to robustly measure the column-dependent space density of obscured AGN for the first time. Finally, we will exploit our leadership in an eMERLIN legacy radio survey and its associated Chandra Large X-ray Program to establish the X-ray and radio properties of AGN down to unprecedented low luminosity levels. On cosmological scales, we will use multi-object spectroscopy to measure the host galaxy properties for the sample of SN Ia provided by the Dark Energy Survey, which will yield the most precise supernova-based cosmological constraints to date. We will also drive time-domain science and supernova cosmology within VEILS, the first (and UK-led) extragalactic infra-red synoptic survey. In addition, we will shed new light on the co-evolution of supermassive black holes and their host galaxies, by identifying the interaction between feedback and mergers in creating the well-known relationship between black hole mass and velocity dispersion, and by establishing the relative importance of internal (e.g. disc instabilities) and external processes (e.g. mergers) for galaxy evolution. Given our long-standing commitment to public engagement with research (PER), we will also develop and deliver high-impact PER activities. These will range from a citizen science project based on X-ray light curves to a high-quality full-dome video illustrating how time-resolved, simultaneous X-ray and optical observations allow us to ``see'' the immediate environment around accreting black holes.