insu-03645338
https://insu.hal.science/insu-03645338
https://insu.hal.science/insu-03645338/document
https://insu.hal.science/insu-03645338/file/stu927.pdf
arxiv:1402.0508
doi:10.1093/mnras/stu927
[INSU] INSU - Institut National des Sciences de l'Univers
[CNRS] CNRS - Centre national de la recherche scientifique
[IAP] Institut d'Astrophysique de Paris
[SORBONNE-UNIVERSITE] Sorbonne Université
[SU-INF-2018] SORBONNE université <2018
[SU-SCIENCES] Faculté des Sciences de Sorbonne Université
[SU-TI] Sorbonne Université - Texte Intégral
[ALLIANCE-SU] Alliance Sorbonne Université
Light cone effect on the reionization 21-cm signal - II. Evolution, anisotropies and observational implications
Datta, Kanan K.
Jensen, Hannes
Majumdar, Suman
Mellema, Garrelt
Iliev, Ilian T.
Mao, Yi
Shapiro, Paul R.
Ahn, Kyungjin
[SDU] Sciences of the Universe [physics]
[SDU.ASTR] Sciences of the Universe [physics]/Astrophysics [astro-ph]
ART
methods: numerical
methods: statistical
cosmology: theory
dark ages
reionization
first stars
diffuse radiation
Astrophysics - Cosmology and Nongalactic Astrophysics
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<SUP>-1</SUP> is ∼7.5 MHz. For k = 0.15 and 0.41 Mpc<SUP>-1</SUP>, the optimum bandwidth is ∼11 and ∼16 MHz, respectively.
2014
2022-04-25
en
Monthly Notices of the Royal Astronomical Society
Oxford University Press (OUP): Policy P - Oxford Open Option A