Astronomy Observation and Theory Consolidated Grant 2012

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This proposal is for a single Consolidated Grant to support themajority of research in Theoretical and Observational Astrophysics atthe Institute of Astronomy (IoA) in Cambridge. The new grant subsumesresearch activity previously supported by STFC under the three genericthemes: "Theory", "X-ray Astrophysics" and "Galaxy Formation andEvolution".The theoretical research profile includes work to understand theorigin of the Universe itself. Members of the IoA are play a leadingrole in the European Space Agency Planck mission, and will lead adefinitive determination of the parameters that both define thegeometry of the Universe and quantify the age, size, dark matter, darkenergy and baryonic content. The research links to one of the keygoals in astrophysics: constraining the properties of the dark matterand dark energy content of the Universe.The Universe today is filled with galaxies, of which our own Milky Wayis a not atypical example. A full understanding of galaxy formationand evolution requires multiple lines of attack. Observations of theresolved stellar populations in the Milky Way and its Local Groupcompanions provide a detailed fossil record of the dynamicalassemblies of the galaxies, the formation of stars, and the buildup ofheavy elements over a wide range of mass scales and initialconditions. At the other end of the scale, observations of distantgalaxies spanning lookback times of up to 12 Gyr provide directmeasurements of the evolution of galaxy populations and the buildup ofstars and metals with cosmic time. Finally, measurements of thelarge-scale star formation and abundance properties of nearby galaxiesform a vital astrophysical bridge between the studies of nearbyresolved stellar populations and the distant high-redshiftinvestigations, by allowing us to characterise the evolutionaryproperties of the Hubble sequence and the complex "gastrophysical"processes that regulate the accretion of gas and the formation ofstars in galaxies.It is now recognised that there is an intimate link between theevolution of galaxies and the origin and properties of super-massiveblack holes, which reside at the centre of the Milky Way and othergalaxies. The regions close to black holes allow the exploration ofphysics at the extremes. The formation and properties of super-massiveblack holes and their relation to the galaxies in which they reside isa research theme that involves theory, X-ray astrophysics andobservational programmes in the grant. The X-ray based research willmeasure the spin of both the super-massive black holes, which powerthe enormous energy emissions from quasars, and the stellar-mass blackholes in binary star systems. This work, based on spectroscopy ofrelativistically-broadened iron lines, will also provide insights intothe accretion phenomena that power the systems.Within galaxies, the grant focuses on star formation, from the giantmolecular clouds which give birth to stars, down to the more detailedinvestigations of the processes that lead to the formation of starsand star clusters within these molecular clouds. The investigationswill combine state-of-the-art numerical simulations with analyticaltheory and a new set of multi-wavelength observations of nearbygalaxies being obtained with the Herschel and Spitzer spaceobservatories under IoA leadership.The quest to study planetary systems around stars and their formationis another key goal. Research activity in the grant extends fromsearches for the elusive brown-dwarf companions to normal hot starsthrough to theoretical work that concentrates on the properties ofdebris discs, discs of asteroids, cometary objects, and dustsurrounding stars. A feature of the research is the investigation ofdebris discs surrounding both stars on the main sequence (where theyspend the majority of their lives) and in the final stages of theirevolution.