A new analytical formalism self-consistently predicts both the ionized fraction x_i(z) and photoionization rate Gamma_HI(z), achieving percent-level accuracy in x_i and 20-30% accuracy in Gamma_HI versus radiative transfer simulations at z less than or equal to 6.
Radiative Transfer in a Clumpy Universe: III. The Nature of Cosmological Ionizing Sources
6 Pith papers cite this work. Polarity classification is still indexing.
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abstract
The history of the transition from a neutral intergalactic medium (IGM) to one that is almost fully ionized can reveal the character of cosmological ionizing sources. We study the evolution of the volume filling factor of HII and HeIII regions in a clumpy IGM, and discuss the implications for rival reionization scenarios of the rapid decline in the space density of radio-loud quasars and of the large population of star-forming galaxies recently observed at z>3. The hydrogen component in a highly inhomogeneous universe is completely reionized when the number of photons emitted above 1 ryd in one recombination time equals the mean number of hydrogen atoms. If stellar sources are responsible for keeping the IGM ionized at z=5, the rate of star formation at this epoch must be comparable or greater than the one inferred from optical observations of galaxies at z=3, and the mean metallicity per baryon in the universe of order 1/500 solar. An early generation of stars in dark matter halos with circular velocities v_circ=50 km/s, possibly one of the main source of UV photons at high-z, could be detectable with the Next Generation Space Telescope. Models in which the quasar emissivity declines rapidly at z>3 predict a late HeII reionization epoch, a feature that could explain the recent detection of patchy HeII Lyman-alpha at z=2.9 by Reimers et al. (1997) and the abrupt change observed by Songaila (1998) at about the same epoch of the SiIV/CIV ratio, but appear unable to provide the required number of hydrogen-ionizing photons at z=5.
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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.
Empirical three-parameter fit to f_esc(M_h,z) yields steep redshift evolution with population-averaged escape fraction rising from ~2% at z=5 to ~9% at z=12.
JWST UV luminosity function calibration of reionization history bounds primordial magnetic fields to √<B²> < 0.27 nG (n_B=-2) and < 0.18 nG (n_B=2) at 95% CL by ruling out double reionization at z≈24.
Using lensed JWST data behind Abell S1063, the UVLF at z~6-11 is fit with gradual quadratic turnover, yielding no evidence for turnover to M_UV=-13.5 at z=6, exclusion limits on turnover models, and lower bounds showing faint galaxies contribute >50% of UV luminosity density and ~64% of ionizing pho
No monotonic reionization history fits Planck τ, patchy kSZ from SPT/ACT, and Lyα endpoint; an early ionization phase at z≳12 relaxes ∑mν<0.39 eV and shifts σ8 via As-τ degeneracy.
citing papers explorer
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A self-consistent analytical model for both the photoionization rate and reionization history
A new analytical formalism self-consistently predicts both the ionized fraction x_i(z) and photoionization rate Gamma_HI(z), achieving percent-level accuracy in x_i and 20-30% accuracy in Gamma_HI versus radiative transfer simulations at z less than or equal to 6.
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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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Steep Redshift Evolution of the Ionizing Escape Fraction at $z = 5$--$12$: Empirical Constraints and Comparison with Simulations
Empirical three-parameter fit to f_esc(M_h,z) yields steep redshift evolution with population-averaged escape fraction rising from ~2% at z=5 to ~9% at z=12.
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JWST Constraints on Primordial Magnetic Fields
JWST UV luminosity function calibration of reionization history bounds primordial magnetic fields to √<B²> < 0.27 nG (n_B=-2) and < 0.18 nG (n_B=2) at 95% CL by ruling out double reionization at z≈24.
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Tilting at the Turnover: Modeling the Faint-End of the UV Luminosity Function Behind Abell s1063 with JWST
Using lensed JWST data behind Abell S1063, the UVLF at z~6-11 is fit with gradual quadratic turnover, yielding no evidence for turnover to M_UV=-13.5 at z=6, exclusion limits on turnover models, and lower bounds showing faint galaxies contribute >50% of UV luminosity density and ~64% of ionizing pho
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A hidden reionization prior biases cosmological inference
No monotonic reionization history fits Planck τ, patchy kSZ from SPT/ACT, and Lyα endpoint; an early ionization phase at z≳12 relaxes ∑mν<0.39 eV and shifts σ8 via As-τ degeneracy.