Galaxy Clusters: Plasma Physics Laboratories and a Grand Challenge for Computational Astrophysics


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  • Speaker: Samuel Skillman (University of Colorado - Boulder, Center for Astrophysics and Space Astronomy)
  • Host Department: Physics
  • Date: 10/21/2013
  • Time: 4:00 PM - 5:00 PM

  • Location: 335 West Hall

  • Description:

    Galaxy clusters are unique astrophysical laboratories that contain many thermal and non-thermal phenomena that demand a coordinated effort from theory, numerical simulations, and observations.  After discussing a few of the major open questions in galaxy cluster formation and evolution, I’ll present our recent work in attempting to model the non-thermal cosmic-ray population present in clusters.  It is proposed that cosmic shocks that propagate through the intracluster medium form through the process of structure formation, and may be capable of accelerating charged particles through diffusive shock acceleration.  These relativistic particles decay and radiate through a variety of mechanisms, and have observational signatures in radio, hard X-ray, and Gamma-ray wavelengths.  Modeling these dynamics require a combination of cosmological hydrodynamics coupled with a model to follow the momentum-space distribution of cosmic ray electrons and protons. We have implemented such a model by combining Enzo, an Adaptive Mesh Refinement hydrodynamics + N-body particle-mesh gravity solver, with a numerical library for cosmic ray transport. I will end with a look to what future observatories in the radio, X-ray, and sub-mm may uncover and what new capabilities our simulations must have to understand fundamental physical processes present in galaxy clusters.