Hydrodynamic Simulations of the Sunyaev‐Zeldovich Effect(s)

Abstract

We have performed a sequence of high-resolution hydrodynamic simulations of structure formation in a Lambda CDM model to study the thermal and kinetic Sunyaev-Zeldovich (SZ) effects. Including only adiabatic gas physics, we demonstrate that our simulations for the thermal effect are converged down to subarcminute scales. In this model, the angular power spectrum of cosmic microwave background (CMB) anisotropies induced by the thermal effect peaks at iota similar or equal to 10(4), and reaches an amplitude just below current observational upper limits. Fluctuations due to the kinetic effect are a factor of similar or equal to 30 lower in power and peak at slightly smaller angular scales. We identify individual SZ sources and compute their counts as a function of source strength and angular size. 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 intergalactic matter (IGM) at high redshift.