The Impact of baryonic physics on the kinetic Sunyaev-Zel'dovich Effect

Poorly understood "baryonic physics" impacts our ability to predict the power spectrum of the kinetic Sunyaev-Zel'dovich (kSZ) effect. We study this in one sample high resolution simulation of galaxy formation and feedback, Illustris. The high resolution of Illustris allows us to probe the kSZ power spectrum on multipoles $\ell =10^3-3\times 10^4$. Strong AGN feedback in Illustris nearly wipes out gas fluctuations at $k\gtrsim1~h~\rm{Mpc}^{-1}$ and at late times, likely somewhat under predicting the kSZ power generated at $z\lesssim 1$. The post-reionization kSZ power spectrum for Illustris is well-fit by $\mathcal{D}^{z _{c}$, even without correcting for the Illustris simulation box size. A challenge going forward will be to accurately model long-wave velocity modes simultaneously with Illustris-like high resolution to capture the complexities of galaxy formation and its correlations with large scale flows.