Hydrodynamical simulations of the Sunyaev-Zel'dovich effect: the kinetic effect

We use hydrodynamical N-body simulations to study the kinetic Sunyaev-Zel'd ovich effect. We construct sets of maps, one square degree in size, in thre e different cosmological models. We confirm earlier calculations that on th e scales studied the kinetic effect is much smaller than the thermal (excep t close to the thermal null point), with an rms dispersion smaller by about a factor of 5 in the Rayleigh-Jeans region. We study the redshift dependen ce of the rms distortion and the pixel distribution at the present epoch. W e compute the angular power spectra of the maps, including their redshift d ependence, and compare them with the thermal Sunyaev-Zel'dovich effect and with the expected cosmic microwave background anisotropy spectrum as well a s with determinations by other authors. We correlate the kinetic effect wit h the thermal effect both pixel-by-pixel and for identified thermal sources in the maps to assess the extent to which the kinetic effect is enhanced i n locations of strong thermal signal.