Completeness-weighted stacking of 56 HAEs at z≃6.2 gives median f_esc^Lyα = 0.106^{+0.066}_{-0.044} with no strong Hα-luminosity dependence and UV-linked galaxy-to-galaxy trends.
Are we witnessing the epoch of reionisation at $z=7.1$ from the spectrum of J1120+0641?
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
We quantify the presence of Ly\alpha\ damping wing absorption from a partially-neutral intergalactic medium (IGM) in the spectrum of the $z=7.08$ QSO, ULASJ1120+0641. Using a Bayesian framework, we simultaneously account for uncertainties in: (i) the intrinsic QSO emission spectrum; and (ii) the distribution of cosmic HI patches during the epoch of reionisation (EoR). For (i) we use a new intrinsic Ly\alpha\ emission line reconstruction method (Greig et al.), sampling a covariance matrix of emission line properties built from a large database of moderate-$z$ QSOs. For (ii), we use the Evolution of 21-cm Structure (EOS; Mesinger et al.) simulations, which span a range of physically-motivated EoR models. We find strong evidence for the presence of damping wing absorption redward of Ly\alpha\ (where there is no contamination from the Ly\alpha\ forest). Our analysis implies that the EoR is not yet complete by $z=7.1$, with the volume-weighted IGM neutral fraction constrained to $\bar{x}_{\rm H\,{\scriptsize I}} = 0.40\substack{+0.21 -0.19}$ at $1\sigma$ ($\bar{x}_{\rm H\,{\scriptsize I}} = 0.40\substack{+0.41 -0.32}$ at $2\sigma$). This result is insensitive to the EoR morphology. Our detection of significant neutral HI in the IGM at $z=7.1$ is consistent with the latest Planck 2016 measurements of the CMB Thompson scattering optical depth (Planck Collaboration XLVII).
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Analysis of JWST/NIRSpec Prism spectra for 25 z>=10 galaxies finds burstiness correlates with strong UV lines, short depletion times, and DLA-induced redshift biases of 0.39 and 0.14 with marginal impact on UV luminosity density.
Long gamma-ray bursts imply a higher cosmic star formation rate density at z>6 than galaxy surveys detect, sufficient to drive reionization with moderate ionizing efficiency and escape fraction, implying a large population of undetected faint galaxies.
Review of machine learning applications for analyzing Lyman-alpha forest observations to probe cosmology, reionization, and dark matter.
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Subaru meets JWST: A Direct Measurement of Ly$\boldsymbol{\alpha}$ Escape Fraction at $\boldsymbol{z\simeq6.2}$ with Dual Narrow-Band Imaging
Completeness-weighted stacking of 56 HAEs at z≃6.2 gives median f_esc^Lyα = 0.106^{+0.066}_{-0.044} with no strong Hα-luminosity dependence and UV-linked galaxy-to-galaxy trends.
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JWST spectroscopy of galaxies at $z>10$: Damped Ly$\alpha$ absorbers reveal efficient star formation and hidden redshift biases
Analysis of JWST/NIRSpec Prism spectra for 25 z>=10 galaxies finds burstiness correlates with strong UV lines, short depletion times, and DLA-induced redshift biases of 0.39 and 0.14 with marginal impact on UV luminosity density.
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Gamma-ray bursts reveal the history and faint contributors of cosmic reionization
Long gamma-ray bursts imply a higher cosmic star formation rate density at z>6 than galaxy surveys detect, sufficient to drive reionization with moderate ionizing efficiency and escape fraction, implying a large population of undetected faint galaxies.
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Machine Learning Techniques for Astrophysics and Cosmology: Lyman-$\alpha$ forest
Review of machine learning applications for analyzing Lyman-alpha forest observations to probe cosmology, reionization, and dark matter.