The explosion mechanism of massive stars

Physics Colloquium 14th October 2016 delivered by Professor Thierry Foglizzo The supernova explosion of massive stars is primarily powered by the gravitational contraction of their core into a neutron star, before the formation of a black hole. Despite numerous observations of supernovae in distant galaxies, the underlying mechanism is still a major challenge to theorists. Prof Foglizzo will review the state of the art, with an emphasis on the multidimensional effects of hydro and MHD instabilities. Non axisymmetric one-armed instabilities known as the Standing Accretion Shock Instability and the corotation instability are able to redistribute angular momentum radially even for moderate rotation rates. Numerical simulations of simplified models are used to evaluate their effect on the explosion and the pulsar spin. Surprisingly, both instabilities can be illustrated with a simple hydraulic experiment based on a shallow water analogy. Results are analyzed in view of the constraints on the angular momentum budget set by stellar evolution on the one hand and by the spin properties of pulsars on the other hand. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/

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The Department of Physics public lecture series. An exciting series of lectures about the research at Oxford Physics take place throughout the academic year. Looking at topics diverse as the creation of the universe to the science of climate change. Features episodes previously published as: (1) 'Oxford Physics Alumni': "Informal interviews with physics alumni at events, lectures and other alumni related activities." (2) 'Physics and Philosophy: Arguments, Experiments and a Few Things in Between': "A series which explores some of the links between physics and philosophy, two of the most fundamental ways with which we try to answer our questions about the world around us. A number of the most pertinent topics which bridge the disciplines are discussed - the nature of space and time, the unpredictable results of quantum mechanics and their surprising consequences and perhaps most fundamentally, the nature of the mind and how far science can go towards explaining and understanding it. Featuring interviews with Dr. Christopher Palmer, Prof. Frank Arntzenius, Prof. Vlatko Vedral, Dr. David Wallace and Prof. Roger Penrose."