Astrophysics at St Andrews: 2012-2014

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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 are learning 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 are studying the signatures of this interaction, which will help us to understand how planets form and evolve. We are investigating the physics of mineral clouds and lightning in atmospheres of cool brown dwarf stars and extrasolar planets. These processes alter our view of planetary systems and will help us understand dust and lightning in volcanic eruptions on Earth. We are using 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 are conducting a survey of 350,000 galaxies to study how their structure emerges. We will learn how galaxies form into their characteristic shapes of flat discs, spiral arms and central bulges. This will help us to understand more exotic phenomena such as the central engines of galaxies, the supermassive black holes that lurk in their central regions, with the aim of understanding how they grow. We are studying how gravity works on the scale of galaxies and the universe. Stars orbit in galaxies so fast that there does not appear to be enough mass to hold the galaxies together. On larger scales, the expansion of the universe itself is accelerating. These puzzles tell us that although we understand gravity on small scales, well enough to send space probes to other planets, it may be different on the larger scales of galaxies and beyond. We are studying alternatives to current ideas of Dark Matter and Dark Energy, comparing our predictions with observations to test how gravity works. Thus we address key questions in the Science Roadmap: What are the laws of physics in extreme conditions? How do galaxies, stars and planets form and evolve? Are we alone in the Universe? Our science programme exploits major international and space observatories such as ASKAP, eMERLIN, Herschel, Kepler, Spitzer, HST, future facilities including ALMA, JWST, SKA, and PLATO.