Scholars 2009

2009 Past - Astrophysics, History of the Universe

Lemze Doron

Tel Aviv University, Department of Astronomy and Astrophysics 

“Mass and Light Distributions in Clusters of Galaxies”

Update November 2010: 

Galaxy clusters are the largest gravitationally bound systems in the universe. Their collective and intrinsic properties are of prime interest; these include their mass and redshift distributions (commonly referred to as the mass function), gas mass fraction, and the spatial profiles of their various density components. The intrinsic properties can be determined in several ways. In Dr. Lemze's work he uses multi datasets (e.g. lensing, X-ray, galactic dynamics) to precisely determine the DM, gas, and galaxies properties. This is done in different and independent methods to increase the reliability and decrease the uncertainties. These properties can give insight not only on clusters themselves but also on the universe and its components.

For example they can shed light on the collisionless nature of DM and baryons. Another example is that theoretical expectations and detailed hydrodynamical simulations indicate clearly that the mean relative baryon and dark matter (DM) densities in clusters provide good estimates of the global values. He also uses powerful cosmological hydrodynamical simulations runs on supercomputers to compare between cosmological and cluster models expectations and observation. Another aspect of Dr. Lemze's work is to focus on novel theoretical approaches to understand the nature of DM better and to constrain various cosmological models.