The thermal Sunyaev Zel'dovich effect power spectrum in light of Planck

Understand

(Abridged) The amplitude of the thermal Sunyaev Zel'dovich effect (tSZ) power spectrum is extremely sensitive to the abundance of galaxy clusters and therefore to fundamental cosmological parameters that control their growth, such as sigma_8 and Omega_m.

• Here we explore the sensitivity of the tSZ power spectrum to important non-gravitational ('sub-grid') physics by employing the cosmo-OWLS suite of large-volume cosmological hydrodynamical simulations, run in both the Planck and WMAP7 best-fit cosmologies.
• On intermediate and small angular scales (ell > ~1000, or theta < ~10 arcmin), accessible with the South Pole Telescope and the Atacama Cosmology Telescope, the predicted tSZ power spectrum is highly model dependent, with AGN feedback having a particularly large effect.
• However, at large scales, observable with the Planck telescope, the effects of sub-grid physics are minor.