Intermittence of the Map of Kinetic Sunyaev-Zel'dovich Effect and Turbulence of IGM

TL;DR

This paper explores how the kinetic Sunyaev-Zel'dovich effect can be used to detect turbulence in the intergalactic medium by analyzing structure functions and intermittence in simulated maps.

Contribution

It demonstrates that the kSZ effect exhibits strong intermittence consistent with turbulence scaling laws, providing a new method to probe IGM turbulence observationally.

Findings

kSZ maps show strong intermittence following She-Leveque scaling

tSZ maps exhibit weak intermittence

combined SZ effects reveal significant intermittence at small angular scales

Abstract

We investigate the possibility of detecting the turbulent state of the IGM with the kinetic Sunyaev-Zel'dovich (kSZ) effect. Being sensitive to the divergence-free component of the momentum field of the IGM, the kSZ effect might be used to probe the vorticity of the turbulent IGM. With cosmological hydrodynamical simulation in the concordance $\Lambda$CDM universe, we find that the structure functions of 2D kSZ maps show strong intermittence, and the intermittent exponents follow a law similar to the She-Leveque scaling formula of fully developed turbulence. We also find that the intermittence is weak in the maps of thermal Sunyaev-Zel'dovich (tSZ) effect. Nevertheless, the superposition of the kSZ and tSZ effects still contain significant intermittence. We conclude that the turbulent behavior of the IGM may be revealed by the observation of SZ effect on angular scales equal to or less than 0.5 arcminute, corresponding to the multipole parameter $l\geq 2 \times10^4$.