ARTISTICS · Strong gravitational lensing from galaxy clusters: a tool for cosmology

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Project objective

The statistical properties of gravitational arcs in galaxy clusters is sensitive to several factors which depend on cosmology, like the geometry of the Universe, the number of clusters at redshifts where they are most efficient for lensing and the internal structure of lenses. Arc statistics therefore offers a potentially powerful cosmological tool. However, several studies have been done so far, attempting to constrain cosmological parameters using the statistical properties of lensed arcs but their result s turned out to be in contrast with what suggested by many other cosmological tests, evidencing a profound lack in our understanding of the physical properties and evolution of galaxy clusters which determine their lensing properties. The goal of this proj ect is close this gap by combining a large amount of observational data with detailed theoretical modeling. On the one hand, we will test suitable software for automatic arc-detection and classification, and we will use them for analyzing the data from the Sloan Digital Sky Survey. We will update and extend existing observations and we will develop tools for data analysis which will be usable for manipulating both simulated and real images. On the other hand, we will use numerical simulations for studying the lensing properties of realistic cluster models in different cosmological frameworks. We will investigate the lensing effects by galaxy clusters obtained from high-resolution N-body and (magneto-) hydrodynamical simulations. We will evaluate the impact on arc statistics of dynamical processes arising in clusters, like mergers. We will use large cosmological volumes for studying projection effects due to the alignment of matter along the line of sight and we will try to understand which role is played by magnetic fields and radiative cooling. Finally, we will study arc statistics in cosmological models with dark energy, aiming at evaluating the compatibility of these models with the observed number of arcs.

Original text from CORDIS.

Participants

• MAX-PLANCK-GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V. · MUENCHENCoordinatorGermany

Links

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