2019/05/31 by Weitian Li, Haiguang Xu, Zhixian Ma +11 · 11 citations
Physics and Astronomy · #Astrophysics and Cosmic Phenomena #Dark Ages #Epoch (astronomy) #Galaxies: Formation, Evolution, Phenomena #Halo #Radio Astronomy Observations and Technology #Radio astronomy #Radio frequency #Radio telescope #Redshift #Reionization #astro-ph.CO
paper · pdf · doi:10.3847/1538-4357/ab21bc
published in The Astrophysical Journal 879(2), 104 (IOP Publishing) · main text 18 pages, 16 figures, 2 appendixes; updated to match the ApJ edited version
openalex created_date 2019/05/29 · arxiv created 2019/06/11 · openalex publication_date 2019/07/11 · arxiv updated 2019/07/17 · openalex updated_date 2026/08/06
The overwhelming foreground contamination is one of the primary impediments to probing the Epoch of Reionization (EoR) through measuring the redshifted 21 cm signal. Among various foreground components, radio halos are less studied and their impacts on the EoR observations are still poorly understood. In this work, we employ the Press–Schechter formalism, merger-induced turbulent reacceleration model, and the latest SKA1-Low layout configuration to simulate the SKA "observed" images of radio halos. We calculate the one-dimensional power spectra from simulated images and find that radio halos can be about 10 4 , 10 3 , and 10 2.5 times more luminous than the EoR signal on scales of in the 120–128, 154–162, and 192–200 MHz bands, respectively. By examining the two-dimensional power spectra inside properly defined EoR windows, we find that the power leaked by radio halos can still be significant, as the power ratios of radio halos to the EoR signal on scales of can be up to about 230%–800%, 18%–95%, and 7%–40% in the three bands when the 68% uncertainties caused by the variation of the number density of bright radio halos are considered. Furthermore, we find that radio halos located inside the far side lobes of the station beam can also impose strong contamination within the EoR window. In conclusion, we argue that radio halos are severe foreground sources and need serious treatments in future EoR experiments.