Open AccessReionization history from coupled cosmic microwave background/21‐cm line data
Author(s) -
Salvaterra R.,
Ciardi B.,
Ferrara A.,
Baccigalupi C.
Publication year - 2005
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2005.09089.x
Subject(s) - reionization , physics , cosmic microwave background , astronomy , astrophysics , cosmic cancer database , cosmic background radiation , microwave , line (geometry) , intergalactic medium , galaxy , redshift , optics , anisotropy , geometry , mathematics , quantum mechanics
We study cosmic microwave background (CMB) secondary anisotropies produced by inhomogeneous reionization by means of cosmological simulations coupled with the radiative transfer code crash . The reionization history is consistent with the Wilkinson Microwave Anisotropy Probe Thomson optical depth determination. We find that the signal arising from this process dominates over the primary CMB component for l ≳ 4000 and reaches a maximum amplitude of l ( l + 1) C l /2π≃ 1.6 × 10 −13 on arcmin scales (i.e. l as large as several thousands). We then cross‐correlate secondary CMB anisotropy maps with neutral hydrogen 21‐cm line emission fluctuations obtained from the same simulations. The two signals are highly anticorrelated on angular scales corresponding to the typical size of H ii regions (including overlapping) at the 21‐cm map redshift. We show how the CMB/21‐cm cross‐correlation can be used: (i) to study the nature of the reionization sources; (ii) to reconstruct the cosmic reionization history; (iii) to infer the mean cosmic ionization level at any redshift. We discuss the feasibility of the proposed experiment with forthcoming facilities.