Turbulence in ENZO simulations using Adaptive Mesh Refinement

THE ADOPTION OF AN IMPLEMENTED MESH REFINMENT TECHNIQUE
PRODUCES MORE TURBULENCE IN ENZO CLUSTER SIMULATIONS

In Vazza et al.(2009) we show that adopting an extra refinement criterion working on velocity jumps
slightly changes the innermost thermal structure of simulated galaxy clusters. In particular, we found

- innermost gas density is reduced by 10% compared to cluster simulated with AMR;
- innermost gas temperature and entropy are 10% larger;
- turbulent energy is 50-200% higher (depending on radius).


TURBULENCE SHOWS SPECTRAL SIGNATURES SIMILAR TO KOLMOGOROV TURBULENCE

We measured structure functions and power spectra over nearly two order of magnitude, finding
signatures of a turbulent cascade, from ~ Mpc scales to ~10kpc scales.
  Fluid instabilities injected by infalling clummps and crossing shocks are likely the main sources of turbulent motions in the ICM.


THE INJECTION OF TURBULENCE AND THERMAL ENERGY AT SHOCKS
DO CORRELATE IN TIME

With the exquisite spatial resolution up to 2 virial radii from the center of our simulated clusters,
we were able to follow in detail the evolution of merger and accretion shocks, and to correlated them
with the evolution of the power spectrum of turbulent energy, finding that the bulk
of both energy release is related to the major merger event which forms the bulk
of cluster mass.



see Vazza et al.2009 A&A