We use cookies to ensure that we give you the best experience on our website. By continuing to browse this repository, you give consent for essential cookies to be used. You can read more about our Privacy and Cookie Policy.

Durham Research Online
You are in:

Statistics of neutral regions during hydrogen reionization.

Nusser, A. and Benson, A.J. and Sugiyama, N. and Lacey, C. (2002) 'Statistics of neutral regions during hydrogen reionization.', Astrophysical journal letters., 580 (2). L93-L96.


We present predictions for two statistical measures of the hydrogen reionization process at high redshift. The first statistic is the number of neutral segments identified in spectra of high-redshift QSOs as a function of their length. The second is the cross-correlation of neutral regions with possible sources of ionizing radiation. These independent probes are sensitive to the topology of the ionized regions. If reionization proceeded from high- to low-density regions, then the cross-correlation will be negative, while if voids were ionized first we expect a positive correlation and a relatively small number of long neutral segments. We test the sensitivity of these statistics for reionization by stars in high-redshift galaxies. The flux of ionizing radiation emitted from stars is estimated by identifying galaxies in an N-body simulation using a semianalytic galaxy formation model. The spatial distribution of ionized gas is traced in various models for the propagation of the ionization fronts. A model with ionization proceeding from high- to low-density regions is consistent with the observations of Becker et al., while models in which ionization begins in the lowest density regions appear to be inconsistent with the present data. Further data are required to confirm this result.

Item Type:Article
Keywords:Cosmology: observations, Cosmology: theory, Dark matter, Intergalactic medium, Large-scale structure of universe, Quasars: absorption lines.
Full text:(VoR) Version of Record
Download PDF
Publisher Web site:
Publisher statement:© 2002. The American Astronomical Society. All rights reserved.
Date accepted:No date available
Date deposited:12 February 2015
Date of first online publication:December 2002
Date first made open access:No date available

Save or Share this output

Look up in GoogleScholar