Post on 05-Jan-2016
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 ‘78White & Rees ‘78
Fall & Efstathiou ‘80
Semi-a
nalyt
ic m
odel
of g
alax
y fo
rmat
ion
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 ~ Mb
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 -- 300 Gbytes
To make merger histories need 50 outputs -- 15 Tbytes
Post-processing will allow some reduction but not bya large factor
Final product: a Virtual universe
Galaxy population in 500 Mpc/h volume – complete to L* + 5 at all redshifts and wavelenghtsIncluding spectrophotometric, structural and chemicaland clustering properties of all the galaxies.
Conclusions
The construction of virtual universes to aid the analysis of real data is becoming increasinglycommon.
The required sizes of these kinds of datasets is becoming very large.
The size of the collaborations that generate and utilisethese 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