Patchy Kinetic Sunyaev–Zel’dovich Effect with Controlled Reionization History and Morphology
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 throu...
Published in: | The Astrophysical Journal |
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Main Authors: | , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
IOP Publishing
2023
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Subjects: | |
Online Access: | https://doi.org/10.3847/1538-4357/ac8481 https://doaj.org/article/87888a2c9a4d4f43ac81f190f0fb642c |
Summary: | 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 < z _mid < 8.9 using the Planck 2018 Thomson optical depth result (95% CL). Then, assuming z _mid = 8, we find that the amplitude of ${D}_{{\ell }=3000}^{\mathrm{pkSZ}}$ scales linearly with the duration of reionization Δ _z and is consistent with the 1 σ upper limit from South Pole Telescope (SPT) results up to Δ _z < 5.1 (Δ _z encloses 5%–95% ionization). Moreover, a shorter λ _mfp can lead to a ∼10% lower ${D}_{{\ell }=3000}^{\mathrm{pkSZ}}$ and a flatter slope in the ${D}_{{\ell }=3000}^{\mathrm{pkSZ}}-{{\rm{\Delta }}}_{z}$ scaling relation, thereby affecting the constraints on Δ _z at ℓ = 3000. Allowing z _mid and λ _mfp to vary simultaneously, we get spectra consistent with the SPT result (95% CL) up to Δ _z = 12.8 (but A _z > 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. |
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