Gaussian Process Reconstruction of Reionization History

Abstract

We reconstruct the history of reionization using Gaussian process regression. Using the UV luminosity data compilation from Hubble Frontiers Fields we reconstruct the redshift evolution of UV luminosity density and thereby the evolution of the source term in the ionization equation. This model-independent reconstruction rules out single power-law evolution of the luminosity density but supports the logarithmic double power-law parametrization. We obtain reionization history by integrating ionization equations with the reconstructed source term. Using optical depth constraint from Planck Cosmic Microwave Background observation, measurement of UV luminosity function integrated till truncation magnitude of -17 and -15, and derived ionization fraction from high redshift quasar, galaxies and gamma-ray burst observations, we constrain the history of reionization. In the conservative case we find the constraint on the optical depth as $\tau =0.052\pm 0.001\pm 0.002$ at 68% and 95% confidence intervals. We find the redshift duration between 10% and 90% ionization to be $2.05_{-0.21-0.30}^{+0.11+0.37}$. Longer duration of reionization is supported if UV luminosity density data with truncation magnitude of -15 is used in the joint analysis. Our results point out that even in a conservative reconstruction, a combination of cosmological and astrophysical observations can provide stringent constraints on the epoch of reionization.

10 pages, 4 figures and 1 table

References in corpus (16)

• The James Webb Space Telescope
• A luminous quasar at a redshift of z = 7.085
• Model-independent evidence in favor of an end to reionization by z~6
• Gaussian Process Cosmography
• Line Emitting Galaxies Beyond a Redshift of 7: An Improved Method for Estimating the Evolving Neutrality of the Intergalactic Medium
• Inferences on the Timeline of Reionization at z~8 From the KMOS Lens-Amplified Spectroscopic Survey
• Rapid Decline of Lyman-alpha Emission Toward the Reionization Era
• Hubble Frontier Fields First Complete Cluster Data: Faint Galaxies at $z\sim 5-10$ for UV Luminosity Functions and Cosmic Reionization
• Nonparametric Reconstruction of the Dark Energy Equation of State
• LiteBIRD: JAXA's new strategic L-class mission for all-sky surveys of cosmic microwave background polarization
• Probing the Neutral Fraction of the IGM with GRBs during the Epoch of Reionization
• Cosmic Reionization After Planck and Before JWST: An Analytic Approach
• Reionization inference from the CMB optical depth and E-mode polarization power spectra
• Witnessing the reionization history using Cosmic Microwave Background observation from Planck
• Cosmic histories of star formation and reionization: An analysis with a power-law approximation
• The THESEUS space mission: science goals, requirements and mission concept

Cited by in corpus (4)

• How to use GP: Effects of the mean function and hyperparameter selection on Gaussian Process regression
• Gaussian Processes Reconstruction of the Dark Energy Potential
• Dark Twilight Joined with the Light of Dawn to Unveil the Reionization History
• Does the Reionization Model Influence the Constraints on Dark Matter Decay or Annihilation?