Studying Reionization with Ly-alpha Emitters

Abstract

We show that observations of high-redshift Ly-alpha emitters (LAEs) have the potential to provide definitive evidence for reionization in the near future. Using 200 Mpc radiative transfer simulations, we calculate the effect that patchy reionization has on the line profile, on the luminosity function, and, most interestingly, on the clustering of emitters for several realistic models of reionization. Reionization increases the measured clustering of emitters, and we show that this enhancement would be essentially impossible to attribute to anything other than reionization. Our results motivate looking for the signature of reionization in existing LAE data. We find that for stellar reionization scenarios the angular correlation function of the 58 LAEs in the Subaru Deep Field z = 6.6 photometric sample is more consistent with a fully ionized universe (mean volume ionized fraction x_i = 1) than a universe with x_i < 0.5 at >2-sigma confidence level. Measurements in the next year on Subaru will increase their z = 6.6 LAE sample by a factor of five and tighten these limits. If the clustering signature of reionization is detected in a LAE survey, a comparison with a Lyman-break or a H-alpha survey in the same field would confirm the reionization hypothesis. We discuss the optimal LAE survey specifications for detecting reionization, with reference to upcoming programs.

24 pages, 17 figures, accepted by MNRAS

References in corpus (6)

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• Probing Reionization with the 21 cm-Galaxy Cross Power Spectrum
• Quasar Proximity Zones and Patchy Reionization
• LCDM predictions for galaxy protoclusters I: the relation between galaxies, protoclusters and quasars at z~6
• Lyman-alpha Emitters During the Early Stages of Reionization
• Will point sources spoil 21 cm tomography?
• A Flat Photoionization Rate at 2<z<4.2: Evidence for a Stellar-Dominated UV Background and Against a Decline of Cosmic Star Formation Beyond z~3
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• Lyman-alpha Damping Wing Constraints on Inhomogeneous Reionization
• Effect of the intergalactic environment on the observability of Ly-alpha emitters during reionization
• Mapping Neutral Hydrogen During Reionization with the Ly-alpha Emission from Quasar Ionization Fronts
• Signatures of reionization on Lyman alpha emitters
• The ionizing background at the end of overlap
• The clustering of the first galaxy halos
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• Oxygen pumping II: Probing the Inhomogeneous Metal Enrichment at the Epoch of Reionization with High Frequency CMB Observations
• Constraining Gravitational and Cosmological Parameters with Astrophysical Data