Making a virtual Universe Adrian Jenkins - ICC, Durham University
Outline Introduction: Modelling a galaxy population Example of an application Hubble volume simulation Future projects: Millennium simulation
Introduction Galaxy formation Modelling galaxy populations
Galaxy Formation Cosmological model ( , , h) dark matter Formation and evolution of galaxies Primordial fluctuations / (M, t) N-body/gasdynamics simulations Semi-analytics (+N-body simulation) Dark matter halos
Halo Merger History John Helly
White & Rees ‘78 Fall & Efstathiou ‘80 Semi-analytic model of galaxy formation
Halo Merger History John Helly
Cooling onto a disk Halos merge Galaxies merge; if major merger, spheroid forms with starburst New disk may form by further cooling
Galaxies in a Virgo N-body simulation Observable properties of galaxies in each N- body halo computed using the SA model: colour B-V; size ~ M b Galaxies trace filaments Red galaxies in clusters Benson, Frenk, Baugh, Cole & Lacey ‘01 Z = 0
3000 Mpc/h ΛCDM Hubble Volume Simulation A virtual universe: Hubble volume simulations 2dF redshift survey
2dF vs mocks from Hubble vol simulation
The 2dF galaxy power spectrum Galaxy power spectrum in redshift space, convolved with survey window, inclunding non-linear effects
Future Plans Millennium simulation: 10 billion particles
Data sizes: Each output Gbytes To make merger histories need 50 outputs Tbytes Post-processing will allow some reduction but not by a large factor Final product: a Virtual universe Galaxy population in 500 Mpc/h volume – complete to L* + 5 at all redshifts and wavelenghts Including spectrophotometric, structural and chemical and clustering properties of all the galaxies.
Conclusions The construction of virtual universes to aid the analysis of real data is becoming increasingly common. The required sizes of these kinds of datasets is becoming very large. The size of the collaborations that generate and utilise these kinds of data is growing larger.
Future Collaborations EC Framework 6 network - Virgo institutions + Paris, Padova, Warsaw, Talin, Harvard, Michigan, McMaster, Victoria DEISA - linking IBM SP4s in Europe including HPCx Virgo/EPCC/RZG
Virtual Universe
Example 2: 2dF galaxy groups