2008/02/29 by Hiroyuki Tashiro, Nabila Aghanim, M. Langer +4
Physics and Astronomy · #Amplitude #Anisotropy #Astronomy #Astrophysics #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Galaxies: Formation, Evolution, Phenomena #Galaxy #Optics #Physics #Polarization (electrochemistry) #Radio Astronomy Observations and Technology #Redshift #Reionization #Spectral density #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2008.13606.x
published as Mon.Not.Roy.Astron.Soc.389:469-477,2008
openalex publication_date 2008/07/28 · arxiv created 2009/01/15 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The cosmic microwave background (CMB) polarization and the 21-cm line fluctuations are powerful probes of cosmological reionization. We study how the cross-correlation between the CMB polarization (E modes) and the 21-cm line fluctuations can be used to gain further understanding of the reionization history, within the framework of inhomogeneous reionization. Since the E-mode polarization reflects the amplitude of the quadrupole component of the CMB temperature fluctuations, the angular power spectrum of the cross-correlation exhibits oscillations at all multipoles. The first peak of the power spectrum appears at the scale corresponding to the quadrupole at the redshift, which is probed by the 21-cm line fluctuations. The peak reaches its maximum value in redshift when the average ionization fraction of the universe is about half. On the other hand, on small scales, there is a damping that depends on the duration of reionization. Thus, the cross-correlation between the CMB polarization and the 21-cm line fluctuations has the potential to accurately constrain the epoch and the duration of reionization.