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Cited by 527

The DOI matches its Crossref record; 40 of the 40 references it cites were found in a registry or an index.

Evolution of the Ionizing Background and the Epoch of Reionization from the Spectra of [ITAL][CLC]z[/CLC][/ITAL] ∼ 6 Quasars

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Fan, Xiaohui, Narayanan, Vijay K., Strauss, Michael A., White, Richard L., Becker, Robert H., Pentericci, Laura, Rix, Hans-Walter·2002·The Astronomical Journal
DOI 10.1086/339030
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Abstract

We study the process of cosmic reionization and estimate the ionizing background in the intergalactic medium (IGM) using the Lyman series absorption in the spectra of the four quasars at 5.7 < z < 6.3 discovered by the Sloan Digital Sky Survey. We derive the redshift evolution of the ionizing background at high redshifts, using both semianalytic techniques and cosmological simulations to model the density fluctuations in the IGM. The existence of the complete Lyα Gunn-Peterson (GP) trough in the spectrum of the z = 6.28 quasar SDSS 1030+0524 indicates a photoionization rate (Γ -12 in units of 10 -12 s -1 ) at z ∼ 6 lower than 0.08, at least a factor of 6 smaller than the value at z ∼ 3. The Lyβ and Lyγ GP troughs give an even stronger limit Γ -12 ≲ 0.02 due to their smaller oscillator strengths, indicating that the ionizing background in the IGM at z ∼ 6 is more than 20 times lower than that at z ∼ 3. Meanwhile, the volume-averaged neutral hydrogen fraction increases from 10 -5 at z ∼ 3 to greater than 10 -3 at z ∼ 6. At this redshift, the mass-averaged neutral hydrogen fraction is larger than 1%; the mildly overdense regions (δ > 3) are still mostly neutral, and the comoving mean free path of ionizing photons is shorter than 8 Mpc. Comparison with simulations of cosmological reionization shows that the observed properties of the IGM at z ∼ 6 are typical of those in the era at the end of the overlap stage of reionization when the individual H II regions merge. Thus z ∼ 6 marks the end of the reionization epoch. The redshift of reionization constrains the small-scale power of the mass-density fluctuations and the star-forming efficiency of the first generation of objects.

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Metadata

Authors
Fan, X., Narayanan, V. K., Strauss, M. A., White, R. L., Becker, R. H., Pentericci, L., & Rix, H.-W.
Venue
The Astronomical Journal
Publisher
American Astronomical Society
Published
2002-03
Volume
123
Issue
3
Pages
1247-1257
ISSN
  • 0004-6256 (ISSN-L)
  • 1538-3881
DOI
10.1086/339030
OpenAlex
W1560669094
Cited by
527
References
40
FWCI
44.85
Type
journal article
Language
en
Open access
bronze

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CoChat. (2026). Citation check: Evolution of the Ionizing Background and the Epoch of Reionization from the Spectra of [ITAL][CLC]z[/CLC][/ITAL] ∼ 6 Quasars. https://app.cochat.ai/papers/10.1086/339030
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Fan, X., Narayanan, V. K., Strauss, M. A., White, R. L., Becker, R. H., Pentericci, L., & Rix, H.-W. (2002). Evolution of the Ionizing Background and the Epoch of Reionization from the Spectra of [ITAL][CLC]z[/CLC][/ITAL] ∼ 6 Quasars. The Astronomical Journal. https://doi.org/10.1086/339030

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