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Planck intermediate results. XLVII. Planck constraints on reionization history

5 Pith papers cite this work. Polarity classification is still indexing.

5 Pith papers citing it
abstract

We investigate constraints on cosmic reionization extracted from the Planck cosmic microwave background (CMB) data. We combine the Planck CMB anisotropy data in temperature with the low-multipole polarization data to fit LCDM models with various parameterizations of the reionization history. We obtain a Thomson optical depth tau=0.058 +/- 0.012 for the commonly adopted instantaneous reionization model. This confirms, with only data from CMB anisotropies, the low value suggested by combining Planck 2015 results with other data sets and also reduces the uncertainties. We reconstruct the history of the ionization fraction using either a symmetric or an asymmetric model for the transition between the neutral and ionized phases. To determine better constraints on the duration of the reionization process, we also make use of measurements of the amplitude of the kinetic Sunyaev-Zeldovich (kSZ) effect using additional information from the high resolution Atacama Cosmology Telescope and South Pole Telescope experiments. The average redshift at which reionization occurs is found to lie between z=7.8 and 8.8, depending on the model of reionization adopted. Using kSZ constraints and a redshift-symmetric reionization model, we find an upper limit to the width of the reionization period of Dz < 2.8. In all cases, we find that the Universe is ionized at less than the 10% level at redshifts above z~10. This suggests that an early onset of reionization is strongly disfavoured by the Planck data. We show that this result also reduces the tension between CMB-based analyses and constraints from other astrophysical sources.

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representative citing papers

Planck 2018 results. VI. Cosmological parameters

astro-ph.CO · 2018-07-17 · accept · novelty 5.0

Final Planck CMB data confirms the flat 6-parameter ΛCDM model with Ω_c h² = 0.120 ± 0.001, Ω_b h² = 0.0224 ± 0.0001, n_s = 0.965 ± 0.004, τ = 0.054 ± 0.007, H_0 = 67.4 ± 0.5 km/s/Mpc, and no strong evidence for extensions.

The Lumina Project: CMB Optical Depth Fluctuations from Patchy Reionization

astro-ph.CO · 2026-05-18 · unverdicted · novelty 4.0

The Lumina simulation shows that explicit light-cone integrations produce a CMB optical depth 7% higher than volume-weighted ionization histories, with the excess accumulating near redshift 8 and mass-weighted estimates capturing most of the difference.

citing papers explorer

Showing 5 of 5 citing papers.

  • Direct Collapse Black Hole Candidates from Decaying Dark Matter hep-ph · 2025-09-29 · unverdicted · none · ref 106 · internal anchor

    Axion dark matter decay injects 1-13.6 eV photons that suppress H2, enabling atomic cooling halos and direct collapse black hole seeds for axion masses 24.5-26.5 eV and couplings down to 4e-12/GeV.

  • Constraints on Neutrino Physics from DESI DR2 BAO and DR1 Full Shape astro-ph.CO · 2025-03-18 · conditional · none · ref 199 · internal anchor

    DESI DR2 BAO and full-shape data plus CMB yield ∑m_ν < 0.0642 eV (95% CL) under ΛCDM, in 3σ tension with oscillation lower limits, relaxed to <0.163 eV in w0waCDM.

  • Planck 2018 results. VI. Cosmological parameters astro-ph.CO · 2018-07-17 · accept · none · ref 298

    Final Planck CMB data confirms the flat 6-parameter ΛCDM model with Ω_c h² = 0.120 ± 0.001, Ω_b h² = 0.0224 ± 0.0001, n_s = 0.965 ± 0.004, τ = 0.054 ± 0.007, H_0 = 67.4 ± 0.5 km/s/Mpc, and no strong evidence for extensions.

  • The Lumina Project: CMB Optical Depth Fluctuations from Patchy Reionization astro-ph.CO · 2026-05-18 · unverdicted · none · ref 57 · internal anchor

    The Lumina simulation shows that explicit light-cone integrations produce a CMB optical depth 7% higher than volume-weighted ionization histories, with the excess accumulating near redshift 8 and mass-weighted estimates capturing most of the difference.

  • BROOM: a python package for model-independent analysis of microwave astronomical data astro-ph.CO · 2026-04-15 · unverdicted · none · ref 5

    BROOM is a Python package that applies ILC and GILC techniques for model-independent separation of CMB, SZ, and foreground signals in microwave data along with diagnostic and simulation utilities.