Open AccessLight‐cone anisotropy in 21‐cm fluctuations during the epoch of reionization
Author(s) -
Barkana Rennan,
Loeb Abraham
Publication year - 2006
Publication title -
monthly notices of the royal astronomical society: letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.067
H-Index - 122
eISSN - 1745-3933
pISSN - 1745-3925
DOI - 10.1111/j.1745-3933.2006.00222.x
Subject(s) - reionization , anisotropy , physics , light cone , astrophysics , brightness , spectral density , epoch (astronomy) , line of sight , redshift , astronomy , optics , stars , galaxy , statistics , mathematics , particle physics
The delay in light traveltime along the line of sight generates an anisotropy in the power spectrum of 21‐cm brightness fluctuations from the epoch of reionization. We show that when the fluctuations in the neutral hydrogen fraction become non‐linear at the later stages of reionization, the light‐cone anisotropy becomes of the order of unity on scales ≳50 comoving Mpc. During this period the density fluctuations and the associated anisotropy generated by peculiar velocities are negligible in comparison.