Measuring Omega Baryon from the Helium Lyman-Alpha Forest
Astrophysics
2007-05-23 v1
Abstract
A new method to extract Omega_b from high redshift intergalactic absorption is described, based on the distribution of HeII Ly-alpha optical depths in the voids in the ionization zone of quasars. A preliminary estimate from recent HST-STIS spectra of PKS 1935-692 at z=3 gives Omega_b h^2 = 0.013^{+0.002}_{-0.001} (1-sigma statistical errors, for a Lambda-CDM cosmology with additional systematic uncertainties) consistent with other estimates.
Cite
@article{arxiv.astro-ph/9911394,
title = {Measuring Omega Baryon from the Helium Lyman-Alpha Forest},
author = {James W. Wadsley and Craig J. Hogan and Scott F. Anderson},
journal= {arXiv preprint arXiv:astro-ph/9911394},
year = {2007}
}
Comments
7 Pages, 2 Figures, to appear in the proceedings of Clustering at High Redshift, IGRAP International Conference, Marseilles, June 29-July 2, 1999