Simulating the Sunyaev‐Zeldovich Effect(s): Including Radiative Cooling and Energy Injection by Galactic Winds

Abstract

We present results on the thermal and kinetic Sunyaev-Zeldovich (SZ) effects from a sequence of high-resolution hydrodynamic simulations of structure formation, including cooling, feedback, and metal injection. These simulations represent a self-consistent thermal model that incorporates ideas from the "preheating" scenario while preserving good agreement with the low-density intergalactic medium at z ∼ 3 probed by the Lyα forest. Four simulations were performed, at two different resolutions with and without radiative effects and star formation. The long-wavelength modes in each simulation were the same, so we can compare the results on an object-by-object basis. We demonstrate that our simulations are converged to the subarcminute level. The effect of the additional physics is to suppress the mean Comptonization parameter by 20% and to suppress the angular power spectrum of fluctuations by just under a factor of 2 in this model, while leaving the source counts and properties relatively unchanged. We quantify how non-Gaussianity in the SZ maps increases the sample variance over the standard result for Gaussian fluctuations. We identify a large scatter in the Y-M relation that will be important in searches for clusters using the SZ effect(s).