Contribution of Radio Halos to the Foreground for SKA EoR Experiments

Abstract

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 re-acceleration 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 $0.1{\text{Mpc}}^{-1}<k<2{\text{Mpc}}^{-1}$ 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 $0.5{\text{Mpc}}^{-1}\lesssim k\lesssim 1{\text{Mpc}}^{-1}$ 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.

main text 18 pages, 16 figures, 2 appendixes; updated to match the ApJ edited version

References in corpus (28)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• Observational constraints on Cosmic Reionization
• Turbulence and Magnetic Fields in the Large Scale Structure of the Universe
• Revised equipartition & minimum energy formula for magnetic field strength estimates from radio synchrotron observations
• Compressible Turbulence in Galaxy Clusters: Physics and Stochastic Particle Re-acceleration
• An optimized algorithm for multi-scale wideband deconvolution of radio astronomical images
• The Epoch of Reionization Window: I. Mathematical Formalism
• Foreground simulations for the LOFAR - Epoch of Reionization Experiment
• Revisiting the radio interferometer measurement equation. I. A full-sky Jones formalism
• Real-Time Calibration of the Murchison Widefield Array
• First Season MWA EoR Power Spectrum Results at Redshift 7
• Deep 1.4 GHz VLA Observations of the Radio Halo and Relic in Abell 2256
• Turbulence and Particle Acceleration in Giant Radio Haloes: the Origin of Seed Electrons
• New scaling relations in cluster radio halos and the re-acceleration model
• Gamma rays from clusters of galaxies
• The Matryoshka Run (II): Time Dependent Turbulence Statistics, Stochastic Particle Acceleration and Microphysics Impact in a Massive Galaxy Cluster
• Will point sources spoil 21 cm tomography?
• A giant radio halo in the cool core cluster CL1821+643
• De-contamination of cosmological 21-cm maps
• LOFAR discovery of an ultra-steep radio halo and giant head-tail radio galaxy in Abell 1132
• Self-similar energetics in large clusters of galaxies
• New giant radio sources and underluminous radio halos in two galaxy clusters
• An Efficient Fokker-Planck Solver and its Application to Stochastic Particle Acceleration in Galaxy Clusters
• Can giant radio halos probe the merging rate of galaxy clusters?
• ATCA observations of the MACS-Planck Radio Halo Cluster Project - I. New detection of a radio halo in PLCK G285.0-23.7
• An Improved Statistical Point-Source Foreground Model for the Epoch of Reionization
• Diffuse radio emission in the complex merging galaxy cluster Abell 2069

Cited by in corpus (8)

• Analytical model for cluster radio relics
• Diffuse Radio Emission from Galaxy Clusters in the LOFAR Two-metre Sky Survey Deep Fields
• The bispectrum and 21cm foregrounds during the Epoch of Reionization
• MINOT: Modeling the intracluster medium (non-)thermal content and observable prediction tools
• Understanding the Impact of Semi-numeric Reionization Models when using CNNs
• Contribution of Galactic free-free emission to the foreground for EoR signal in SKA experiments
• A Semi-Analytical Model for the Formation and Evolution of Radio Relics in Galaxy Clusters
• A Monte Carlo Implementation of Galactic Free-Free Emission for the EoR Foreground Models