Science with Large N-body Simulations

1. Science with Large N-body Simulations What could you do with 16K processors and 32 TB RAM? Classical Collisionless N-body Problem • Modelling dynamics of stars and dark matter in galaxies • Following the dynamical evolution of the galaxies in the • cosmological environment over the age of the universe • Understand the origin of the morphological mix of galaxies • spirals, barred galaxies, ellipticals, and irregulars • Modelling interactions of stars and supermassive blackholes • in galactic nuclei -> event rate for gravitational wave detectors Collisional N-body Problem • Gravity plus hard collisions • Formation of the terrestrial planets through build up of planetesimals • Formation of planetary rings (Saturn) – complex dynamical interactions • in ring systems

2. Current work and impact using Mckenzie • 3 parallelized N-body codes – PARTREE, GOTPM, Collisional PARTREE • applications in galaxy dynamics and cosmological structure formation • Hi-resolution cosmological N-body simulations with Jing in Shanghai • Detailed self-consistent mass modelling of Milky Way and M31 with Widrow • Projects studying disk galaxy evolution – bar instability, • disk galaxy heating and evolution in presence of a system of dark satellites, • evolution in presence of a triaxial tumbling dark halo • (grad students O’Neill and Gauthier) • Studies of BH binary formation in merging galaxies (grad student Bonoli) • Other impact • providing illustrations for revised edition of Galaxy Dynamics, • Binney and Tremaine • current production of animation compilation on DVD – ESA released • documentary on 15 years of HST – distribution of up to 10M copies • North American publication