Numerical simulations of cluster mergers
and
their application to Chandra observations
Y. Ascasibar, M. Markevitch and L. Hernquist
Harvard­Smithsonian Center for Astrophysics
Outline
­ Galaxy clusters
­ Theoretical
­ Observed
­ Simulations
­ Initial conditions
­ Preliminary results
Numerical simulations of cluster mergers
Theoretical clusters
­ Spherical symmetry
­ Hydrostatic equilibrium
­ Equation of state
­ Isothermal (beta­bodel)
­ Polytropic (Ascasibar et al. 2003)
Numerical simulations of cluster mergers
Observed clusters
­ Pre­Chandra
­ Cooling flows
­ Post­Chandra
­ Cold fronts
Numerical simulations of cluster mergers
Our goal
­ What's going on in the cores of galaxy clusters?
­ AGN feedback
­ Gas sloshing
­ Do mergers cause gas sloshing?
­ Major ­ Minor Numerical simulations of cluster mergers
Initial conditions
­ Dark matter
­ Hernquist profile
­ Gas
­ Initial guess: Polytropic
­ Cooling term
­ Merger set­up
­ Mass ratio
­ Impact parameter
Numerical simulations of cluster mergers
Preliminary results
Numerical simulations of cluster mergers
Preliminary results
Numerical simulations of cluster mergers
Preliminary results
Numerical simulations of cluster mergers
Preliminary results
Numerical simulations of cluster mergers
Preliminary results
­ It seems that
­ Minor mergers cause gas sloshing
­ Gas sloshing causes cold fronts
­ However
­ Other mechanisms are not excluded Numerical simulations of cluster mergers
Numerical simulations of cluster mergers
and
their application to Chandra observations
Y. Ascasibar, M. Markevitch and L. Hernquist
Harvard­Smithsonian Center for Astrophysics