Inferring the IGM Neutral Fraction at z ~ 6-8 with Low-Luminosity Lyman Break Galaxies

Abstract

We present a Bayesian inference on the neutral hydrogen fraction of the intergalactic medium (IGM), $x_{\text{HI}}$, at $z\sim$ 6-8 using the properties of Lyman break galaxies during the Epoch of Reionization. We use large samples of LBG candidates at $5.5\le z\le 8.2$ with spectroscopy from Keck/DEIMOS and Keck/MOSFIRE. For each galaxy, we incorporate either the Lyman-$\alpha$ equivalent width (EW) for detections or the EW limit spectrum for nondetections to parameterize the EW distribution at various ultraviolet brightnesses for a given redshift. Using our reference sample of galaxy candidates from the ionized universe at $z$ $\sim$ 6.0, we are able to infer $x_{\text{HI}}$ at two redshifts: $z$ $\sim$ 6.7 and $z$ $\sim$ 7.6. This work includes intrinsically faint, gravitationally lensed galaxies at $z$ $\sim$ 6.0 in order to constrain the intrinsic faint-end Ly$\alpha$ EW distribution and provide a comparable population of galaxies to counterparts in our sample that are at higher redshift. The inclusion of faint galaxy candidates, in addition to a more sophisticated modelling framework, allows us to better isolate effects of the interstellar medium and circumgalactic medium on the observed Lyman-$\alpha$ distribution from those of the IGM. We infer an upper limit of $x_{\text{HI}}$ $\le$ 0.25 at $z$ = 6.7 $\pm$ 0.2 and a neutral fraction of $x_{\text{HI}}$ = $0.83_{-0.11}^{+0.08}$ at $z$ = 7.6$\pm$ 0.6, both within 1$\sigma$ uncertainty, results which favor a moderately late and rapid reionization.

11 pages, 7 figures

References in corpus (38)

• The NumPy array: a structure for efficient numerical computation
• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• Observational constraints on Cosmic Reionization
• Model-independent evidence in favor of an end to reionization by z~6
• 3D Lyman-alpha radiation transfer. I. Understanding Lyman-alpha line profile morphologies
• The End of the Reionization Epoch Probed by Ly-alpha Emitters at z=6.5 in the Subaru Deep Field
• Conditions for Reionizing the Universe with A Low Galaxy Ionizing Photon Escape Fraction
• Hydrogen reionisation ends by $z=5.3$: Lyman-$\alpha$ optical depth measured by the XQR-30 sample
• Lyman Alpha Emitting Galaxies as a Probe of Reionization
• Line Emitting Galaxies Beyond a Redshift of 7: An Improved Method for Estimating the Evolving Neutrality of the Intergalactic Medium
• New observations of z~7 galaxies: evidence for a patchy reionization
• Studying Reionization with Ly-alpha Emitters
• Inferences on the Timeline of Reionization at z~8 From the KMOS Lens-Amplified Spectroscopic Survey
• Introducing the THESAN project: radiation-magnetohydrodynamic simulations of the epoch of reionization
• Can the intergalactic medium cause a rapid drop in Lyman alpha emission at z>6?
• Rapid Decline of Lyman-alpha Emission Toward the Reionization Era
• A Significantly Neutral Intergalactic Medium Around the Luminous z=7 Quasar J0252-0503
• Constraining the neutral fraction of hydrogen in the IGM at redshift 7.5
• Accelerated Evolution of Ly$\alpha$ Luminosity Function at $\text{z}\gtrsim 7$ Revealed by the Subaru Ultra-Deep Survey for Ly$\alpha$ Emitters at $\text{z}=7.3$
• Definitive Identification of the Transition between Small- to Large-Scale Clustering for Lyman Break Galaxies
• Imprint of Inhomogeneous Hydrogen Reionization on the Temperature Distribution of the Intergalactic Medium
• An uncontaminated measurement of the escaping Lyman continuum at $z\sim 3$
• The THESAN project: Lyman-alpha emission and transmission during the Epoch of Reionization
• Long Dark Gaps in the Ly$\beta$ Forest at $z<6$: Evidence of Ultra Late Reionization from XQR-30 Spectra
• A VLT/FORS2 view at $z\sim 6$: Lyman-$\alpha$ emitter fraction and galaxy physical properties at the edge of the epoch of cosmic reionization
• The Evolution of the Lyman-Alpha Luminosity Function During Reionization
• Chasing the Tail of Cosmic Reionization with Dark Gap Statistics in the Ly$\alpha$ Forest over $5<z<6$
• LAGER Ly$\alpha$ Luminosity Function at $z\sim 7$, Implications for Reionization
• A Comprehensive Study of Ly$\alpha$ Emission in the High-redshift Galaxy Population
• The VANDELS survey: the relation between UV continuum slope and stellar metallicity in star-forming galaxies at z~3
• Serendipitous Discovery of an Overdensity of Lyman-Alpha Emitters at z~4.8 in the Cl1604 Supercluster Field
• The evolution of rest-frame UV properties, Lya EWs and the SFR-Stellar mass relation at z~2-6 for SC4K LAEs
• Spitzer UltRa Faint SUrvey Program (SURFS UP) I: An Overview
• The MUSE-Wide survey: A measurement of the Ly$\alpha$ emitting fraction among $z>3$ galaxies
• SILVERRUSH XI: Constraints on the Ly$\alpha$ luminosity function and cosmic reionization at $z=7.3$ with Subaru/Hyper Suprime-Cam
• Dark-ages Reionization and Galaxy Formation Simulation XX. The Ly$\alpha$ IGM transmission properties and environment of bright galaxies during the Epoch of Reionization
• Determining the Timescale over Which Stellar Feedback Drives Turbulence in the ISM: A Study of four Nearby Dwarf Irregular Galaxies
• The UV spectral slope beta and stellar population of most active star-forming galaxies at z~4

Cited by in corpus (24)

• Closing in on the sources of cosmic reionization: first results from the GLASS-JWST program
• JADES: Discovery of extremely high equivalent width Lyman-alpha emission from a faint galaxy within an ionized bubble at z=7.3
• The production of ionizing photons in UV-faint z~3-7 galaxies
• The impact of an evolving stellar initial mass function on early galaxies and reionisation
• Deciphering Lyman-$\alpha$ Emission Deep into the Epoch of Reionisation
• Elevated UV luminosity density at Cosmic Dawn explained by non-evolving, weakly mass-dependent star formation efficiency
• Nature and Nurture? Comparing Ly$\alpha$ Detections in UV-Bright and Fainter [O III]+H$\beta$ Emitters at $z\sim 8$ With Keck/MOSFIRE
• Insights into the reionization epoch from cosmic-noon-CIV emitters in the VANDELS survey
• Early Results from GLASS-JWST XXIII: The transmission of Lyman-alpha from UV-faint z ~ 3-6 galaxies
• Constraints on the $z\sim 6-13$ intergalactic medium from JWST spectroscopy of Lyman-alpha damping wings in galaxies
• Evolution of the Lyman-α emitting fraction and UV properties of lensed star-forming galaxies between 2.9 < z < 6.7
• Mapping reionization bubbles in the JWST era I: empirical edge detection with Lyman alpha emission from galaxies
• Mapping reionization bubbles in the JWST era II: inferring the position and characteristic size of individual bubbles
• Explaining JWST star formation history at $z\sim 17$ by modifying $\Lambda$CDM
• Inferring the Distribution of the Ionising Photon Escape Fraction
• Rapid and Late Cosmic Reionization Driven by Massive Galaxies: a Joint Analysis of Constraints from 21-cm, Lyman Line & CMB Data Sets
• Global 21 cm signal: a promising probe of primordial features
• Reionizing islands with inhomogeneous recombinations
• Narrowing the discovery space of the cosmological 21-cm signal using multi-wavelength constraints
• Ly$\alpha$ Emission from [OIII] Emitters Near Reionization: The role of environment in galaxy Ly$\alpha$ detection
• Deep JWST spectroscopy of galaxies in a candidate ionized bubble at $z=8.7$: probing reionization at pMpc scales with Ly$\alpha$ emission
• A Lyman continuum analysis for $\sim 100$ galaxies at $z_{\text{spec}}\sim 3$ in the Abell 2744 Cluster Field
• Double-Peaked Ly$\alpha$ Emission during Reionization Requires Nearby Voids and a Favorable Local Ionizing Background
• Uncertainty-Aware Neural Networks for Fuzzy Dark Matter Model Selection from \texorpdfstring{$x_{\mathrm{HI}}$}{x_HI} Measurements