Computational Planet, Star and Galaxy Formation

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Computational astrophysics enables the astronomer's dream of seeing stars and galaxies come to life and evolve before their eyes.  Young stars can have substantial amounts of gas in disks around them.  With computer simulations we have recently demonstrated that these disks spontaneously fragment under ideal conditions to create giant gas planets larger than Jupiter. Pairs of young stars can nearly collide and shred the disks into a string of brown dwarfs.  These disks and young planetary objects are slow to lose their heat through infrared radiation and so they should be puffed up, a property we now intend to include in our models.  We will also model entire clusters of young stars for a much more realistic and violent planet forming environment!     A major success of recent simulations is the formation of convincing spiral galaxies on a computer.  The simulated galaxies form over billions of years, consuming gas and smaller galaxies in what is regarded as fairly quiet evolution.  As a result they contain thin disks of stars that formed over the age of the universe in a manner consistent with real stellar populations in the Milky Way.  Dramatic merger events can transform these quiet galaxies into the full range of galaxies types seen in the universe and also drive some of their gas and stars into voracious black holes at their centres.  To model these galaxies even better we are developing even more detailed prescriptions for the gas and how it cools, black holes, how stars form and how stars die in energetic supernova explosions.