Using the novel seminumerical code for reionization AMBER, we model the patchy kinetic Sunyaev–Zel’dovich (kSZ) effect by directly specifying the reionization history with the redshift midpoint
The mean free path of ionizing photons,
 Award ID(s):
 1908284
 NSFPAR ID:
 10465031
 Author(s) / Creator(s):
 ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; more »
 Publisher / Repository:
 DOI PREFIX: 10.3847
 Date Published:
 Journal Name:
 The Astrophysical Journal
 Volume:
 955
 Issue:
 2
 ISSN:
 0004637X
 Format(s):
 Medium: X Size: Article No. 115
 Size(s):
 Article No. 115
 Sponsoring Org:
 National Science Foundation
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Abstract z _{mid}, duration Δ_{z}, and asymmetryA _{z}. We further control the ionizing sources and radiation through the minimum halo massM _{h}and the radiation mean free pathλ _{mfp}. AMBER reproduces the freeelectron number density and the patchy kSZ power spectrum of radiation–hydrodynamic simulations at the target resolution (1 Mpch ^{−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, assumingz _{mid}= 8, we find that the amplitude of scales linearly with the duration of reionization Δ_{z}and is consistent with the 1 ${D}_{\mathit{\ell}=3000}^{\mathrm{pkSZ}}$σ upper limit from South Pole Telescope (SPT) results up to Δ_{z}< 5.1 (Δ_{z}encloses 5%–95% ionization). Moreover, a shorterλ _{mfp}can lead to a ∼10% lower and a flatter slope in the ${D}_{\mathit{\ell}=3000}^{\mathrm{pkSZ}}$ scaling relation, thereby affecting the constraints on Δ_{z}at ${D}_{\mathit{\ell}=3000}^{\mathrm{pkSZ}}{\mathrm{\Delta}}_{z}$ℓ = 3000. Allowingz _{mid}andλ _{mfp}to vary simultaneously, we get spectra consistent with the SPT result (95% CL) up to Δ_{z}= 12.8 (butA _{z}> 8 is needed to ensure the end of reionization beforez = 5.5). We show that constraints on the asymmetry require ∼0.1μ k ^{2}measurement accuracy at multipoles other thanℓ = 3000. Finally, we find that the amplitude and shape of the kSZ spectrum are only weakly sensitive toM _{h}under a fixed reionization history and radiation mean free path. 
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