%0 Journal Article
%T Light cone effect on the reionization 21-cm signal - II. Evolution, anisotropies and observational implications
%+ Institut d'Astrophysique de Paris (IAP)
%A Datta, Kanan K.
%A Jensen, Hannes
%A Majumdar, Suman
%A Mellema, Garrelt
%A Iliev, Ilian T.
%A Mao, Yi
%A Shapiro, Paul R.
%A Ahn, Kyungjin
%< avec comité de lecture
%@ 0035-8711
%J Monthly Notices of the Royal Astronomical Society
%I Oxford University Press (OUP): Policy P - Oxford Open Option A
%V 442
%P 1491-1506
%8 2014
%D 2014
%Z 1402.0508
%Z 2014MNRAS.442.1491D
%R 10.1093/mnras/stu927
%K methods: numerical
%K methods: statistical
%K cosmology: theory
%K dark ages
%K reionization
%K first stars
%K diffuse radiation
%K Astrophysics - Cosmology and Nongalactic Astrophysics
%Z Sciences of the Universe [physics]
%Z Sciences of the Universe [physics]/Astrophysics [astro-ph]Journal articles
%X Measurements of the H I 21-cm power spectra from the reionization epoch will be influenced by the evolution of the signal along the line-of-sight direction of any observed volume. We use numerical as well as seminumerical simulations of reionization in a cubic volume of 607 Mpc across to study this so-called light-cone effect on the H I 21-cm power spectrum. We find that the light-cone effect has the largest impact at two different stages of reionization: one when reionization is ∼20 per cent and other when it is ∼80 per cent completed. We find a factor of ∼4 amplification of the power spectrum at the largest scale available in our simulations. We do not find any significant anisotropy in the 21-cm power spectrum due to the light-cone effect. We argue that for the power spectrum to become anisotropic, the light-cone effect would have to make the ionized bubbles significantly elongated or compressed along the line of sight, which would require extreme reionization scenarios. We also calculate the two-point correlation functions parallel and perpendicular to the line of sight and find them to differ. Finally, we calculate an optimum frequency bandwidth below which the light-cone effect can be neglected when extracting power spectra from observations. We find that if one is willing to accept a 10 per cent error due to the light-cone effect, the optimum frequency bandwidth for k = 0.056 Mpc^{-1} is ∼7.5 MHz. For k = 0.15 and 0.41 Mpc^{-1}, the optimum bandwidth is ∼11 and ∼16 MHz, respectively.
%G English
%2 https://insu.hal.science/insu-03645338/document
%2 https://insu.hal.science/insu-03645338/file/stu927.pdf
%L insu-03645338
%U https://insu.hal.science/insu-03645338
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%~ CNRS
%~ IAP
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%~ SU-INF-2018
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