The Sunyaev‐Zeldovich Effect: Simulations and Observations

The Sunyaev-Zeldovich effect (SZ effect) is a complete probe of ionized baryons, the majority of which are likely hiding in the intergalactic medium. We ran a 512 3 Λ cold dark matter simulation using a moving mesh hydro code to compute the statistics of the thermal and kinetic SZ effect such as the power spectra and measures of non-Gaussianity. The thermal SZ power spectrum has a very broad peak at multipole l ~ 2000-10 4 with temperature fluctuations Δ T ~ 15 μK. The power spectrum is consistent with available observations and suggests a high σ 8 ≃ 1.0 and a possible role for nongravitational heating. The non-Gaussianity is significant and increases the cosmic variance of the power spectrum by a factor of ~5 for l < 6000. We explore optimal drift-scan survey strategies for the Array for Microwave Background Anisotropy and their dependence on cosmology. For SZ power spectrum estimation, we find that the optimal sky coverage for 1000 hr of integration time is several hundred square degrees. One achieves an accuracy better than 40% in the SZ measurement of the power spectrum and an accuracy better than 20% in the cross-correlation with Sloan galaxies for 2000 < l < 5000. For cluster searches, the optimal scan rate is around 280 hr deg -2 with a cluster detection rate of one every 7 hr, allowing for a false positive rate of 20% and better than 30% accuracy in the cluster SZ distribution function measurement.