Cosmic Reionization May Still Have Started Early and Ended Late: Confronting Early Onset with CMB Anisotropy and 21 cm Global Signals

Abstract

The global history of reionization was shaped by the relative amounts of starlight released by three halo mass groups: atomic-cooling halos (ACHs) with virial temperatures Tvir > 10^4 K, either (1) massive enough to form stars even after reionization (HMACHs, >~ 10^9 Msun) or (2) less-massive (LMACHs), subject to star formation suppression when overtaken by reionization, and (3) H2-cooling minihalos (MHs) with Tvir < 10^4 K, whose star formation is predominantly suppressed by the H2-dissociating Lyman-Werner (LW) background. Our previous work showed that including MHs caused two-stage reionization - early rise to x ~ 0.1, driven by MHs, followed by a rapid rise, late, to x ~ 1, driven by ACHs - with a signature in CMB polarization anisotropy predicted to be detectable by the Planck satellite. Motivated by this prediction, we model global reionization semi-analytically for comparison with Planck CMB data and the EDGES global 21cm absorption feature, for models with: (1) ACHs, no feedback; (2) ACHs, self-regulated; and (3) ACHs and MHs, self-regulated. Model (3) agrees well with Planck E-mode polarization data, even with a substantial tail of high-redshift ionization, beyond the limit proposed by the Planck Collaboration (2018). No model reproduces the EDGES feature. For model (3), |dTb| <~ 60 mK across the EDGES trough, an order of magnitude too shallow, and absorption starts at higher z but is spectrally featureless. Early onset reionization by Population III stars in MHs is compatible with current constraints, but only if the EDGES interpretation is discounted or else other processes we did not include account for it.

Version accepted to ApJ with minor mod; added references; new figures for H-ionizing UV background prediction

References in corpus (28)

• The Formation of Population III Binaries from Cosmological Initial Conditions
• The observed ionization rate of the intergalactic medium and the ionizing emissivity at z >5: Evidence for a photon starved and extended epoch of reionization
• Primordial Star Formation under the Influence of Far Ultraviolet Radiation: 1540 Cosmological Halos and the Stellar Mass Distribution
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• The Global 21 Centimeter Background from High Redshifts
• Keeping the Universe ionised: Photo-heating and the clumping factor of the high-redshift intergalactic medium
• Radiative transfer simulations of cosmic reionization I: methodology and initial results
• Population III star formation in a Lambda CDM universe, II: Effects of a photodissociating background
• Early Cosmological HII/HeIII Regions and Their Impact on Second-Generation Star Formation
• The Destruction of Cosmological Minihalos by Primordial Supernovae
• Feedback-regulated star formation and escape of LyC photons from mini-haloes during reionisation
• Self-regulated reionization
• Suppression of H_2 Cooling in the Ultraviolet Background
• The Effects of Dark Matter-Baryon Scattering on Redshifted 21 cm Signals
• Results from EDGES High-Band: I. Constraints on Phenomenological Models for the Global $21$ cm Signal
• Constraining the intergalactic medium at $z\approx$ 9.1 using LOFAR Epoch of Reionization observations
• Decoding the X-ray Properties of Pre-Reionization Era Sources
• The influence of streaming velocities and Lyman-Werner radiation on the formation of the first stars
• Foreground Model and Antenna Calibration Errors in the Measurement of the Sky-Averaged λ21 cm Signal at z~20
• The Effects of Population III X-ray and Radio Backgrounds on the Cosmological 21-cm Signal
• Heating and cooling of the intergalactic medium by resonance photons
• Lyman-$\alpha$ coupling and heating at Cosmic Dawn
• Reionization inference from the CMB optical depth and E-mode polarization power spectra
• Formulating and critically examining the assumptions of global 21-cm signal analyses: How to avoid the false troughs that can appear in single spectrum fits
• A tale of two sites -- II: Inferring the properties of minihalo-hosted galaxies with upcoming 21-cm interferometers
• Nonlinear Bias of Cosmological Halo Formation in the Early Universe
• Spatially Extended 21 cm Signal from Strongly Clustered UV and X-Ray Sources in the Early Universe
• Lyalpha heating and its impact on early structure formation

Cited by in corpus (15)

• The Impact of the First Galaxies on Cosmic Dawn and Reionization
• Reionization and galaxy inference from the high-redshift Lyα forest
• Bursty star formation during the Cosmic Dawn driven by delayed stellar feedback
• The short ionizing photon mean free path at z=6 in Cosmic Dawn III, a new fully-coupled radiation-hydrodynamical simulation of the Epoch of Reionization
• Retrieving cosmological information from small-scale CMB foregrounds II. The kinetic Sunyaev Zel'dovich effect
• RELIKE: Reionization Effective Likelihood from Planck 2018 Data
• The role of Pop III stars and early black holes in the 21cm signal from Cosmic Dawn
• Probing the Early History of Cosmic Reionization by Future Cosmic Microwave Background Experiments
• Reionization in the Light of Dark Stars
• Probing the global 21-cm background by velocity-induced dipole and quadrupole anisotropies
• Gravitational wave backgrounds from coalescing black hole binaries at cosmic dawn: an upper bound
• Dispersion Measures of Fast Radio Bursts through the Epoch of Reionization
• Impact of reionization history on constraining primordial gravitational waves in future all-sky cosmic microwave background experiments
• Reionization process dependence of the ratio of CMB polarization power spectra at low-$\ell$
• From Dark Matter Minihalos to Large-Scale Radiative Feedback: A Self-Consistent 3D Simulation of the First Stars and Galaxies using Neural Networks