Patchy Kinetic Sunyaev–Zel’dovich Effect with Controlled Reionization History and Morphology

Abstract

Using the novel semi-numerical code for reionization AMBER, we model the patchy kinetic Sunyaev–Zel’dovich (kSZ) effect by directly specifying the reionization history with the redshift midpoint z _mid , duration Δ _z , and asymmetry A _z . We further control the ionizing sources and radiation through the minimum halo mass M _h and the radiation mean free path λ _mfp . AMBER reproduces the free-electron number density and the patchy kSZ power spectrum of radiation–hydrodynamic simulations at the target resolution (1 Mpc h ^−1 ) with matched reionization parameters. With a suite of (2 Gpc/ h ) ^3 simulations using AMBER, we first constrain the redshift midpoint 6.0 8 is needed to ensure the end of reionization before z = 5.5). We show that constraints on the asymmetry require ∼0.1 μ k ^2 measurement accuracy at multipoles other than ℓ = 3000. Finally, we find that the amplitude and shape of the kSZ spectrum are only weakly sensitive to M _h under a fixed reionization history and radiation mean free path.

Keywords

• Cosmic microwave background radiation
• Sunyaev-Zeldovich effect
• Reionization
• Cosmology