State-of-the-art simulations of cosmological hydrodynamics and of the large-scale distribution of galaxies and Dark Matter will allow us to interpret the large volume of survey science data that will come from SkyMapper and ASKAP, so that we can model galaxy formation and can understand the interplay between galaxies and the intergalactic medium during and after reionisation.

In next few years deep and wide imaging campaigns with facilities such as SkyMapper will discover distant galaxies and quasars. At the same time, spectroscopic studies of bright, high redshift quasars with optical and near-Infrared facilities will probe the intergalactic gas that these early galaxies form from and subsequently interact with. Detailed models of this complex, non-linear interaction are vital for interpreting forthcoming data and guiding future observational programmes. The aim of this project is to perform state-of-the-art cosmological hydrodynamic simulations with P-Gadget3(XXL) to better understand the interplay between galaxies and intergalactic medium (IGM) from redshift z~2 to the Epoch of Reionisation at z=6 and above.

On a similar timescale, the Australian Square Kilometre Array Pathfinder (ASKAP) will see first light. One of the key science drivers for ASKAP will be to survey cold gas in galaxies over the last few billion years of cosmic time – the WALLABY all-sky survey will map the galaxy distribution out to z=0.26, while the DINGO pencil-beam survey will track galaxies out to almost z=1. We are exploiting Australia’s world-class supercomputing facilities to run state-of-the-art cosmological N-body simulations of large (Gpc3) volumes containing 1-100 billion particles using optimized versions of the GADGET code. These simulations provide the dark matter framework within which we model galaxy formation, by building merger trees that track the formation histories of dark matter haloes and coupling these trees to the latest semi-analytical galaxy formation models.

Simulated merger of two galaxies
Simulated X-ray emission from galaxy groups and clusters strung along the cosmic web, showing structures on the largest scales.

CAASTRO Researchers in this Project
Prof. Stuart Wyithe  (Project Leader)
 CAASTRO Member  Node
 Dr. Edoardo Tescari  University of Melbourne
 Mr. Antonios Katsianis  University of Melbourne
 Dr. Emma Ryan-Weber  Swinburne University
 Prof. Chris Power  University of Western Australia 
 Mr. Steven Murray  University of Western Australia 
 Prof. Carlos Frenk  University of Durham (UK) 
 Prof. Brian Schmidt  Australian National University