By measuring the thermal and kinematic Sunyaev– Zel’dovich effects in massive halos, Simons Observatory aims to inform and refine models of galaxy evolution. It will constrain the feedback efficiency in massive galaxies, groups, and clusters, η to 3% uncertainty, and the degree of non-thermal pressure support, p, to 8% uncertainty. Note that no strong limits on these important aspects of galaxy formation currently exist.

The figure shows forecast 1σ uncertainties on the feedback efficiency, ε, (left) and the non-thermal pressure support, α, (right) using SO combined with DESI Luminous Red Galaxies, through cross correlating the thermal and kinematic Sunyaev-Zel’dovich effects. Different colors distinguish between baseline and goal sensitivities and different line styles show the impact of different sky coverages.