Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Extended reionization epoch

  1. Jun 22, 2005 #1


    User Avatar
    Gold Member

    http://arxiv.org/PS_cache/astro-ph/pdf/0506/0506486.pdf [Broken]

    Title: A very extended reionization epoch ?
    Authors: A. Melchiorri, T. Roy Choudhury, P. Serra, A. Ferrara
    Comments: 5 pages, 5 figures

    The recent observations of cross temperature-polarization power spectra of the Cosmic Microwave Background (CMB) made by the WMAP satellite are in better agreement with a high value of the Thomson scattering optical depth \tau \approx 0.17. This value is close to \tau = 0.3, which is taken as the upper limit in the parameter extraction analysis made by the WMAP team. However, models with \tau \sim 0.3 provide a good fit to current CMB data and are not significantly excluded when combined with Large Scale Structure data. By making use of a self-consistent reionization model, we verify the astrophysical feasibility of models with \tau \sim 0.3. It turns out that current data on various observations related to the thermal and ionization history of the intergalactic medium are not able to rule out \tau \sim 0.3. The possibility of a very extended reionization epoch can significantly undermine the WMAP constraints on crucial cosmological parameters such as the Hubble constant, the spectral index of primordial fluctuations and the amplitude of dark matter clustering.
    Last edited by a moderator: May 2, 2017
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?