Simulating the Sunyaev-Zel'dovich effect(s): including radiative cooling and energy injection by galactic winds

Abstract

We present results on the thermal and kinetic Sunyaev-Zel'dovich (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 which incorporates ideas from the `pre-heating' scenario while preserving good agreement with the low density IGM at z~3 probed by the Ly-a 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 that we can compare the results on an object by object basis. We demonstrate that our simulations are converged to the sub-arcminute 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 two 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 which will be important in searches for clusters using the SZ effect(s).