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May 14, 2008 - Dark and Luminous Matter in Clusters of Galaxies - Dr. Andisheh Mahdavi, Postdoctoral Fellow, Department of Physics and Astronomy, University of Victoria
NASA - Dark Matter Mystery Deepens in Cosmic 'Train Wreck' Bio: Andisheh Mahdavi is an observational and computational astrophysicist focusing on clusters of galaxies, the largest gravitationally bound cosmic objects. Mahdavi specializes in marshalling data from orbiting X-ray satellites and ground-based optical and radio telescopes to understand the physics of dark and ordinary matter in clusters Mahdavi received his BA (1995) and PhD (2001) from Harvard University, following which he joined the University of Hawaii as a Chandra Postdoctoral Fellow. Since 2005, he has been at the University of Victoria. Mahdavi has served as a U. S. Fulbright scholar, lived extensively in Europe, the Middle East, and North America, and has received the Harvard Hoopes, Goldberg, and CUE Teaching prizes. |
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Clusters
of galaxies are dominated by dark matter. We can see the gravitational effect of
this dark material on the orbits of cluster members, the thermodynamics of the
hot gas, and the lensed shapes of galaxies behind the cluster. I will
show that combining multi-wavelength data for a single relaxed cluster can yield
powerful constraints on its dark matter distribution and on the equation of
state of the intra-cluster plasma. At the same time, as the bullet cluster
teaches us, multi-wavelength observations of merging clusters can yield
significant and perhaps even more interesting constraints on dark matter
properties. Both relaxed and merging clusters are well-represented in the
Canadian Cluster Comparison Project, an X-ray, optical, and radio survey of
fifty nearby clusters. I will conclude by discussing an unusual, massive, X-ray
bright core nearly devoid of galaxies at the heart of Abell 520, and will
explore its implications for our understanding of the fundamental nature of dark
matter.