Hydrodynamic Simulations of the Sunyaev‐Zeldovich Effect(s)

We have performed a sequence of high resolution hydrodynamic simulations of structure formation in a LCDM model to study the thermal and kinetic Sunyaev-Zel'dovich (SZ) effects. Including only adiabatic gas physics, we demonstrate that our simulations for the thermal effect are converged down to sub-arcminute scales. In this model, the angular power spectrum of CMB anisotropies induced by the thermal effect peaks at l~10⁴, and reaches an amplitude just below current observational upper limits. Fluctuations due to the kinetic effect are a factor of ~30 lower in power and peak at slightly smaller angular scales. We present a preliminary investigation of the consequences of an early epoch of energy injection which tends to suppress power on small angular scales, while giving rise to additional power on large scales from the reheated IGM at high redshift.