# Quantitative Constraints on the Reionization History from the IGM Damping Wing Signature in Two Quasars at z > 7

@article{Davies2018QuantitativeCO,
title={Quantitative Constraints on the Reionization History from the IGM Damping Wing Signature in Two Quasars at z > 7},
author={Frederick B. Davies and Joseph F. Hennawi and Eduardo Ba{\~n}ados and Zarija Luki'c and Roberto Decarli and Xiaohui Fan and Emanuele Paolo Farina and Chiara Mazzucchelli and Hans-Walter Rix and Bram P. Venemans and Fabian Walter and Feige Wang and Jinyi Yang},
journal={arXiv: Cosmology and Nongalactic Astrophysics},
year={2018}
}
• F. Davies, +10 authors Jinyi Yang
• Published 2018
• Physics
• arXiv: Cosmology and Nongalactic Astrophysics
During reionization, neutral hydrogen in the intergalactic medium (IGM) imprints a damping wing absorption feature on the spectrum of high-redshift quasars. A detection of this signature provides compelling evidence for a significantly neutral Universe, and enables measurements of the hydrogen neutral fraction $x_{\rm HI}(z)$ at that epoch. Obtaining reliable quantitative constraints from this technique, however, is challenging due to stochasticity induced by the patchy inside-out topology of… Expand
96 Citations

#### Figures and Tables from this paper

Constraining the Tail End of Reionization Using Lyα Transmission Spikes
• Physics
• The Astrophysical Journal
• 2019
We investigate Lyman-$\alpha$ transmission spikes at $z > 5$ in synthetic quasar spectra, and discuss their connection to the properties of the intergalactic medium and their ability to constrainExpand
Large Ly α opacity fluctuations and low CMB τ in models of late reionization with large islands of neutral hydrogen extending to z < 5.5
High-redshift QSO spectra show large spatial fluctuations in the Ly-alpha opacity of the intergalactic medium on surprisingly large scales at z>~5.5. We present a radiative transfer simulation ofExpand
The Goldilocks problem of the quasar contribution to reionization
• Physics
• 2019
The detection of an unexpectedly large number of faint candidate quasars (QSO) at $z \gtrsim 4$ has motivated Madau and Haardt to investigate a reionization scenario in which active galactic nucleiExpand
Evidence for Low Radiative Efficiency or Highly Obscured Growth of z > 7 Quasars
• Physics
• The Astrophysical Journal
• 2019
The supermassive black holes (SMBHs) observed at the centers of all massive galaxies are believed to have grown via luminous accretion during quasar phases in the distant past. The fraction ofExpand
The impact of scatter in the galaxy UV luminosity to halo mass relation on Ly α visibility during the epoch of reionization
The reionization of hydrogen is closely linked to the first structures in the universe, so understanding the timeline of reionization promises to shed light on the nature of these early objects. InExpand
Implications of the z > 5 Lyman-α forest for the 21-cm power spectrum from the epoch of reionization
• Physics
• Monthly Notices of the Royal Astronomical Society
• 2021
Our understanding of the intergalactic medium at redshifts z = 5–6 has improved considerably in the last few years due to the discovery of quasars with z > 6 that enable Lyman-α forest studies atExpand
Constraining the state of the intergalactic medium during the Epoch of Reionization using MWA 21-cm signal observations
• Physics
• 2021
The Murchison Widefield Array (MWA) team has derived new upper limits on the spherically averaged power spectrum of the 21-cm signal at six redshifts in the range z ≈ 6.5−8.7. We use these upperExpand
Inferences on the timeline of reionization at z ∼ 8 from the KMOS Lens-Amplified Spectroscopic Survey
Detections and non-detections of Lyman alpha (Lyα) emission from z > 6 galaxies (<1 Gyr after the big bang) can be used to measure the timeline of cosmic reionization. Of key interest to measuringExpand
Evidence for short ̃ 1 Myr lifetimes from the He II proximity zones of z ̃ 4 quasars
• Physics
• 2019
The duration of quasar accretion episodes is a key quantity for distinguishing between models for the formation and growth of supermassive black holes, the evolution of quasars, and their potentialExpand
Beyond Optical Depth: Future Determination of Ionization History from the Cosmic Microwave Background.
• Physics, Medicine
• The Astrophysical journal
• 2020
The fundamental limits to which reionization histories can be constrained using only large-scale cosmic microwave background (CMB) anisotropy measurements are explored and future high signal-to-noise measurements of the multipoles 10 ⩽ ℓ < 20 are especially important for breaking the degeneracy between x e min and z re. Expand

#### References

SHOWING 1-10 OF 79 REFERENCES
The Universe is Reionizing at z~7: Bayesian Inference of the IGM Neutral Fraction Using Ly$α$ Emission from Galaxies
We present a new flexible Bayesian framework for directly inferring the fraction of neutral hydrogen in the intergalactic medium (IGM) during the Epoch of Reionization (EoR, z~6-10) from detectionsExpand
Probing re-ionization with quasar spectra: the impact of the intrinsic Lyman α emission line shape uncertainty
• Physics
• 2009
Arguably the best hope of understanding the tail end of the re-ionization of the intergalactic medium (IGM) at redshift z > 6 is through the detection and characterization of the Gunn-PetersonExpand
Lyα damping wing constraints on inhomogeneous reionization
• Physics
• 2007
One well-known way to constrain the hydrogen neutral fraction, x HI , of the high-redshift intergalactic medium (IGM) is through the shape of the red damping wing of the Lya absorption line. WeExpand
Constraints on reionization and source properties from the absorption spectra of z > 6.2 quasars
• Physics
• 2007
We make use of hydrodynamical simulations of the intergalactic medium (IGM) to create model quasar absorption spectra. We compare these model spectra with the observed Keck spectra of three z > 6.2Expand
Cosmic Reionization and Early Star-forming Galaxies: a Joint Analysis of new Constraints From Planck and the Hubble Space Telescope
We discuss new constraints on the epoch of cosmic reionization and test the assumption that most of the ionizing photons responsible arose from high-redshift star-forming galaxies. Good progress hasExpand
Evidence for reionization at z ∼ 6: Detection of a gunn-peterson trough in a z = 6.28 quasar
We present moderate-resolution Keck spectroscopy of quasars at z = 5.82, 5.99, and 6.28, discovered by the Sloan Digital Sky Survey (SDSS). We find that the Ly? absorption in the spectra of theseExpand
Evidence of Gunn–Peterson damping wings in high-z quasar spectra: strengthening the case for incomplete reionization at z ∼ 6–7
• Physics
• 2013
The spectra of several high-redshift (z>6) quasars have shown evidence for a Gunn-Peterson (GP) damping wing, indicating a substantial mean neutral hydrogen fraction (x_HI > 0.03) in the z ~ 6Expand
Quasar ionization front Lyα emission in an inhomogeneous intergalactic medium
• Physics
• 2016
The conditions within the ionization front of a quasar during reionization (T � 30,000 K, neutral hydrogen fraction xH I � 0.5) are ideal for producing Lyα emission via collisional ex- citation ofExpand
Reionization of the Intergalactic Medium and the Damping Wing of the Gunn-Peterson Trough
Observations of high-redshift quasars show that the intergalactic medium (IGM) must have been reionized at some redshift z > 5. If a source of radiation could be observed at the rest-frame LyαExpand
A Fundamental Test for Galaxy Formation Models: Matching the Lyman-α Absorption Profiles of Galactic Halos Over Three Decades in Distance
• Physics
• 2018
Author(s): Sorini, D; Onorbe, J; Hennawi, JF; Lukic, Z | Abstract: © 2018. The American Astronomical Society. All rights reserved.. Galaxy formation depends critically on the physical state of gas inExpand