ASTROPHYSICS

The landscape of cosmology has changed dramatically over the last decades. The increasing application of ever more precise numerical simulations in conjunction with big observational projects established the current paradigm. The universe started out hot, dense and almost homogeneous as observations of cosmic microwave background revealed. The density perturbations grow and eventually form galaxies and galaxy clusters.

This gravitational collapse quickly becomes non-linear, entangling the information of the initial state further and further. Hence it is non-trivial to follow this formation of structure which connects the initial density distribution with the one we observe today by surveying the distribution of galaxies.

A team of scientists at the Leibniz Institute for Astrophysics in Potsdam improved and combined methods to simulate the formation of the actual distribution of galaxies and galaxy clusters. This combination of methods together with the parallel computing facilities available at GCS member centre JSC allowed them to simulate the density distribution in the local universe up to distances of 670 million light-years as shown in shades of red in the Figure. The simulated galaxy clusters and the surrounding large scale well matches the observed one as shown in the figure.

This work and future simulations with the same method with higher resolution will serve as a laboratory for studying the local density distribution and its influence on the formation of galaxies – especially faint ones which are only observable in the local universe.