Astronomy at St Andrews 2015-2018

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The St Andrews astronomy group is interested in questions of origins: where do galaxies, stars and planets come from, and what fundamental physics explains their formation? We are world leaders in solving intricate mathematical problems, and we use novel methods such as observations at very high precision and simulations with super-computers. We are joined by other groups across Scotland via the Scottish Universities Physics Alliance (SUPA), and internationally, in searching for hot and cool Earth-sized planets, homing in on habitable worlds where life could exist.Our research spans a wide range of size scales, from discovering planetary systems around stars a few light years away to measuring the force of gravity acting on the whole universe. We discover `hot Jupiters' by using robotic wide-angle cameras that monitor thousands of stars to find those that briefly dim each time an orbiting planet passes in front of its parent star. We discover cooler and smaller more Earth-like planets, using robotic telescopes to watch gravitational lenses, exploiting Einstein's prediction that a planet drifting across the sightline to a distant background star bends its light. We learn about how planets form by looking at the radiation from dust grains and pebbles, which are either in the process of forming planets or, like our comets, remnants of the planet forming process.Young stars have strong magnetic fields that interact with orbiting planets and their own magnetic fields. We study the signatures of thisinteraction to understand how planets form and evolve. We investigate the physics of mineral clouds and lightning in atmospheres of cool brown dwarf stars and extrasolar planets, processes altering our view of planetary systems and help us understand dust and lightning in volcanic eruptions on Earth. We use observations and numerical simulations to study how stars form in galaxies and how feedback from young stars drives a dynamic, bubbling interstellar medium, the dusty gas from which new stars are born. We include energetic supernova explosions when massive stars die and the ionising radiation from massive stars that heats the gas in the galaxy to temperatures above than 10,000 degrees Centigrade.On cosmological scales, we conduct large scale galaxy surveys to study how their structure emerges, forming their characteristic shapes of flat discs, spiral arms and central bulges. We study the central engines of galaxies, the supermassive black holes that lurk in their hearts, to understand how they grow and how they affect the host galaxy evolution. We study how gravity works both in galaxies and in the universe. Stars orbit in galaxies so fast that there appears to be too little mass to hold the galaxies together. On larger scales, our expanding universe is accelerating. We understand gravity on small scales, well enough to send space probes to other planets, but these puzzles challenge our understanding of gravity on the larger scales of galaxies and beyond. We investigate alternatives to current ideas of Dark Matter and Dark Energy, comparing our predictions with observations to test how gravity works.Thus we address all four of the STFC Science Roadmap Challenges: How did the Universe begin and how is it evolving? How do stars and planetary systems develop and is life unique to our planet? What are the fundamental constituents and fabric of the universe and how do they interact? How can we explore and understand the extremes of the universe? What are the laws of physics in extreme conditions? How do galaxies, stars and planets form and evolve? Are we alone in the Universe? We exploit major international and space observatories (ALMA, APEX, ASKAP, e-MERLIN, CFHT, ESO, CHARA, HARPS, HST, Gaia, Herschel, JCMT, Kepler, LCOGT, SMA, SOFIA, Suzaku, Swift, Spitzer, VLA, XMM) and future facilities including EUCLID, JWST, SKA, and PLATO.