The SZ effect with anisotropic distributions and high energy electrons

Abstract

Future observations of the Sunyaev-Zeldovich (SZ) effect promise ever improving measurements in terms of both sensitivity and angular resolution. As such, it is increasingly relevant to model `higher-order' contributions to the SZ effect. This work examines the effects of high-energy non-thermal electron distributions and those of anisotropic electron and photon distributions on the SZ signals. Analytic forms of the anisotropic scattering kernels for photons and electrons have been derived and investigated. We present a method for determining the anisotropic contributions through a spherical harmonic decomposition to arbitrary angular multipoles, and discuss the behaviour of these scattering kernels. We then carry out an exploration of various simplistic models of high energy non-thermal electron distributions, and examine their anisotropic behaviour. The kinematic SZ in the relativistic regime is studied using the kernel formulation allowing us to clarifying the role of kinematic corrections to the scattering optical depth. We finally present a release of an updated and refined version of SZpack including a new integrated Python interface and new modules for the calculation of various SZ signals, including those described in this paper.