Cosmological, 480^3 Particle Simulation
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A Tree+SPH High-Resolution Simulation of the Cosmic Web

Stefano Borgani, Astronomy Department Trieste
Antonaldo Diaferio, Physics Department Torino
Klaus Dolag, Astronomy Department Padova
Laura Moscardini, Astronomy Department Bologna
Giuseppe Murante, INAF - Astronomical Observatory Torino
Volker Springel, Max Planck Institute Munich
Giuseppe Tormen, Astronomy Department Padova
Luca Tornatore, Astronomy Department Trieste
Paolo Tozzi, INAF - Astronomical Observatory Trieste


We are conducting a cosmological hydrodynamical simulation of a representative volume of the Universe, with high enough resolution to describe in detail the X-ray and Sunyaev-Zeldovich (SZ) properties of the baryonic intergalactic medium in groups and clusters of galaxies and within large-scale filaments. We are using the Tree+SPH code GADGET, developed by V. Springel, to simulate a box of size 192 Mpc/h on a side with about 220 millions gas and dark matter particles, for a standard flat LCDM model. We use a Plummer-equivalent softening length of 7.5 kpc/h so as to correctly compute gravitational and hydrodynamical forces down to a scale corresponding to about 2 per cent of the virial radius of a rich cluster. The GADGET code has a fully adaptive and local time-stepping and includes the effect of radiative cooling, cooling/heating by a uniform evolving UV background, star formation, a recipe to account for the multi-phase nature of the inter-stellar medium, where star formation takes place, feedback and metal enrichment from type-II supernova explosions and the effect of galactic winds.
Our simulation can be used for (a) studing of the contribution of diffuse gas in filamentary structures to the soft X-ray background; (b) studing of the physics of the ICM, through the analysis of the X-ray properties of clusters and groups of galaxies; (c) the analysis of the SZ effect from filaments and collapsed structures, with the twofold aim of studying the ICM properties and of addressing the reconstruction of the CMB power spectrum from the Planck surveyor observations.

Project Description

Simulation Features

Code GADGET (N-Body + SPH)
Number of particles 2x4803
Box Size 192 Mpc/h
Spatial Resolution 7.5 Kpc/h
Cosmological Model Lambda CDM


Quant. Slice Biggest Cluster