Auswirkungen der Gasdynamik auf den Gravitationslinseneffekt von Galaxienhaufen; Bestimmung physikalischer Haufeneigenschaften durch Analyse des Linseneffekts und des Haufengases

• Applicant: Professor Dr. Matthias Bartelmann
• Subject Area: Astrophysics and Astronomy
• Term: from 2004 to 2005
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 5439710

Given reasonably precise knowledge of the fundamental cosmological parameters, it seems inevitable that 96% of the matter in the universe is cold dark matter, and that the expansion of the universe accelerates, driven by some form of dark energy which may or may not be described by a cosmological constant or some more general form of quintessence. Two important cosmological questions regard the composition of the dark matter and the nature of the dark energy. Galaxy clusters are an important class of objects for studying these questions because they are still evolving, thus reflecting the structure formation rate since dark energy started dominating the cosmic expansion, and they are dominated by dark matter well into their cores. Strong gravitational lensing is among the most promising methods for analysing clusters because of its non-linear sensitivity to the details of the matter distribution. The intracluster gas may erase cluster substructures and symmetrise cluster mass distributions and thus severely affect the strong-lensing properties of clusters. Using cluster simulations without and with the gas component, we will quantify this influence and investigate the relation between strong lensing and cluster observables related to the intracluster gas, like the X-ray emission and the thermal Sunyaev-Zeldovich effect.

• DFG Programme: Research Grants