The Physics of the Intracluster Medium: Theory & Computation

August 23-25, 2010

340 West Hall

University of Michigan, Ann Arbor, Central Campus

Organized by: The Michigan Center for Theoretical Physics at the University of Michigan in Ann Arbor

Clusters of galaxies are the largest equilibrated structures in the Universe. Despite the enormous energy input from supermassive black holes, they retain their gaseous matter and behave essentially as "closed boxes".  Clusters are therefore good astrophysical "laboratories" at the crossroads of astrophysics and cosmology.

Our understanding of the physics of the ICM remains incomplete, particularly the physics of the core where cooling, heating and transport processes strongly interact.  There is rich phenomenology that remains poorly understood:  the statistics of cool cores, the presence of radio relic sources, radio mini-halos in cool core clusters, the distribution of metals, and Halpha filaments in clusters.  Non-thermal pressure support due to magnetic fields, turbulence, and cosmic rays is also an open question.

The theoretical studies of the physics of the ICM progressed beyond ideal hydrodynamics. The bestiary of ICM-related plasma instabilities includes magnetothermal instability, heat flux buoyancy instability, gyrothermal, firehose and cosmic-ray driven instabilities. The "microphysical" plasma processes and magnetic fields are known to control the mixing of AGN bubbles with the ICM and the ICM heating and can now be studied using modern MHD codes.

The objective of the workshop is to bring together a number of theoretical/computational astrophysicists, experts in plasma physics and a select number of observers to exchange expertise via informal discussions and talks, and to facilitate collaborations among the participants, who share closely related interests in the physics of the ICM and AGN feedback. Topics to be considered at the workshop include:

- cold fronts and turbulence in the ICM
- relative role of AGN (bubbles,jets), thermal conduction and
   viscosity in heating the ICM
- role of plasma instabilities
- the physics of the coupling between the mechanical energy of the AGN
and the thermal energy of the ICM
- the connection between AGN feedback and star formation
- the evolution and amplification of magnetic fields in the ICM
- powering Halpha filaments
- numerical methods for modeling cluster plasma
- non-thermal pressure, cosmic rays/non-thermal particles and radio halos