Contamination of the Epoch of Reionization power spectrum in the presence of foregrounds

Abstract

We construct foreground simulations comprising spatially correlated extragalactic and diffuse Galactic emission components and calculate the `intrinsic' (instrument-free) two-dimensional spatial power spectrum and the cylindrically and spherically averaged three-dimensional k-space power spectra of the Epoch of Reionization (EoR) and our foreground simulations using a Bayesian power spectral estimation framework. This leads us to identify a model dependent region of optimal signal estimation for our foreground and EoR models, within which the spatial power in the EoR signal relative to foregrounds is maximised. We identify a target field dependent region, in k-space, of intrinsic foreground power spectral contamination at low k_perp and k_parallel and a transition to a relatively foreground-free intrinsic EoR window in the complement to this region. The contaminated region of k-space demonstrates that simultaneous estimation of the EoR and foregrounds is important for obtaining statistically robust estimates of the EoR power spectrum; biased results will be obtained from methodologies that ignore their covariance. Using simulated observations with frequency dependent uv-coverage and primary beam, with the former derived for HERA in 37-antenna and 331-antenna configuration, we recover instrumental power spectra consistent with their intrinsic counterparts. We discuss the implications of these results for optimal strategies for unbiased estimation of the EoR power spectrum.

25 pages, 16 figures, accepted for publication in MNRAS

References in corpus (21)

• Cosmic Reionization and Early Star-Forming Galaxies: A Joint Analysis of New Constraints from Planck and Hubble Space Telescope
• Model-independent evidence in favor of an end to reionization by z~6
• Efficient Simulations of Early Structure Formation and Reionization
• How accurately can 21 cm tomography constrain cosmology?
• The Epoch of Reionization Window: I. Mathematical Formalism
• The Very Large Array Low-frequency Sky Survey Redux (VLSSr)
• Foreground simulations for the LOFAR - Epoch of Reionization Experiment
• 21CMMC: an MCMC analysis tool enabling astrophysical parameter studies of the cosmic 21 cm signal
• A Method for 21cm Power Spectrum Estimation in the Presence of Foregrounds
• Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array
• Blind foreground subtraction for intensity mapping experiments
• The Deep SWIRE Field I. 20cm Continuum Radio Observations: A Crowded Sky
• An Improved Method for 21cm Foreground Removal
• Spectral Index of the Diffuse Radio Background Measured From 100 to 200 MHz
• Non-parametric foreground subtraction for 21cm epoch of reionization experiments
• Foreground Model and Antenna Calibration Errors in the Measurement of the Sky-Averaged λ21 cm Signal at z~20
• A Fast Method for Power Spectrum and Foreground Analysis for 21 cm Cosmology
• The impact of Galactic synchrotron emission on CMB anisotropy measurements. I. Angular power spectrum analysis of total intensity all-sky surveys
• The ionizing background at the end of overlap
• Adding Context to JWST Surveys with Current and Future 21cm Radio Observations
• Foreground removal for Square Kilometre Array observations of the Epoch of Reionization with the Correlated Component Analysis

Cited by in corpus (9)

• Spherical Harmonic Analyses of Intensity Mapping Power Spectra
• An Improved Statistical Point-Source Foreground Model for the Epoch of Reionization
• A Bayesian approach to high fidelity interferometric calibration II: demonstration with simulated data
• All Sky Modelling Requirements for Bayesian 21 cm Power Spectrum Estimation with BayesEoR
• Contribution of Galactic free-free emission to the foreground for EoR signal in SKA experiments
• Simulations of primary beam effects on the cosmic bispectrum phase observed with the Hydrogen Epoch of Reionization Array
• A Bayesian approach to high fidelity interferometric calibration I: mathematical formalism
• A Monte Carlo Implementation of Galactic Free-Free Emission for the EoR Foreground Models
• BayesEoR: Bayesian 21-cm Power Spectrum Estimation from Interferometric Visibilities