Foreground Contamination in Interferometric Measurements of the Redshifted 21 cm Power Spectrum

Abstract

Subtraction of astrophysical foreground contamination from "dirty" sky maps produced by simulated measurements of the Murchison Widefield Array (MWA) has been performed by fitting a 3rd-order polynomial along the spectral dimension of each pixel in the data cubes. The simulations are the first to include the unavoidable instrumental effects of the frequency-dependent primary antenna beams and synthesized array beams. They recover the one-dimensional spherically-binned input redshifted 21 cm power spectrum to within approximately 1% over the scales probed most sensitively by the MWA (0.01 < k < 1 Mpc^-1) and demonstrate that realistic instrumental effects will not mask the EoR signal. We find that the weighting function used to produce the dirty sky maps from the gridded visibility measurements is important to the success of the technique. Uniform weighting of the visibility measurements produces the best results, whereas natural weighting significantly worsens the foreground subtraction by coupling structure in the density of the visibility measurements to spectral structure in the dirty sky map data cube. The extremely dense uv-coverage of the MWA was found to be advantageous for this technique and produced very good results on scales corresponding to |u| < 500 wavelengths in the uv-plane without any selective editing of the uv-coverage.

Replaced with version accepted by ApJ. 19 pages, including 3 figures

References in corpus (15)

• Cosmological Parameter Estimation Using 21 cm Radiation from the Epoch of Reionization
• Multifrequency analysis of 21 cm fluctuations from the Era of Reionization
• Foreground simulations for the LOFAR - Epoch of Reionization Experiment
• A Method for Separating the Physics from the Astrophysics of High-Redshift 21cm Fluctuations
• Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array
• Twenty-one centimeter tomography with foregrounds
• Power Spectrum Sensitivity and the Design of Epoch of Reionization Observatories
• The Sensitivity of First Generation Epoch of Reionization Observatories and Their Potential for Differentiating Theoretical Power Spectra
• Improving Foreground Subtraction in Statistical Observations of 21 cm Emission from the Epoch of Reionization
• Spectral Index of the Diffuse Radio Background Measured From 100 to 200 MHz
• The 21 centimeter emission from the reionization epoch: extended and point source foregrounds
• De-contamination of cosmological 21-cm maps
• Predictions on the angular power spectrum of clustered extragalactic point sources at CMB frequencies from flat and all--sky 2D-simulations
• The impact of Galactic synchrotron emission on CMB anisotropy measurements. I. Angular power spectrum analysis of total intensity all-sky surveys
• 21 cm Tomography of the High-Redshift Universe with the Square Kilometer Array

Cited by in corpus (152)

• Reionization and Cosmology with 21 cm Fluctuations
• Fundamental Physics with the Square Kilometre Array
• Bright Source Subtraction Requirements For Redshifted 21 cm Measurements
• What Next-Generation 21 cm Power Spectrum Measurements Can Teach Us About the Epoch of Reionization
• A Per-Baseline, Delay-Spectrum Technique for Accessing the 21cm Cosmic Reionization Signature
• Science with the Murchison Widefield Array
• Upper limits on the 21-cm Epoch of Reionization power spectrum from one night with LOFAR
• The Epoch of Reionization Window: I. Mathematical Formalism
• PAPER-64 Constraints on Reionization: The 21cm Power Spectrum at z=8.4
• Data Analysis for Precision 21 cm Cosmology
• Imaging the Epoch of Reionization: limitations from foreground confusion and imaging algorithms
• Deep multi-redshift limits on Epoch of Reionisation 21cm Power Spectra from Four Seasons of Murchison Widefield Array Observations
• The Epoch of Reionization Window: II. Statistical Methods for Foreground Wedge Reduction
• A Sensitivity and Array-Configuration Study for Measuring the Power Spectrum of 21cm Emission from Reionization
• The impact of point source subtraction residuals on 21 cm Epoch of Reionization estimation
• Overcoming real-world obstacles in 21 cm power spectrum estimation: A method demonstration and results from early Murchison Widefield Array data
• The GMRT-EoR Experiment: A new upper limit on the neutral hydrogen power spectrum at z~8.6
• Foregrounds for observations of the cosmological 21 cm line: I. First Westerbork measurements of Galactic emission at 150 MHz in a low latitude field
• A Method for 21cm Power Spectrum Estimation in the Presence of Foregrounds
• Opening the 21cm EoR Window: Measurements of Foreground Isolation with PAPER
• The signature of the first stars in atomic hydrogen at redshift 20
• First Season MWA EoR Power Spectrum Results at Redshift 7
• A study of fundamental limitations to statistical detection of redshifted HI from the epoch of reionization
• Foregrounds in Wide-Field Redshifted 21 cm Power Spectra
• The 21-cm signature of the first stars during the Lyman-Werner feedback era
• Realistic Simulations of the Galactic Polarized Foreground: Consequences for 21-cm Reionization Detection Experiments
• An Improved Method for 21cm Foreground Removal
• CHIPS: The Cosmological HI Power Spectrum Estimator
• The Epoch of Reionization
• Foregrounds for observations of the cosmological 21 cm line: II. Westerbork observations of the fields around 3C196 and the North Celestial Pole
• The Rise of the First Stars: Supersonic Streaming, Radiative Feedback, and 21-cm Cosmology
• Characterizing Foreground for redshifted 21-cm radiation: 150 MHz GMRT observations
• Power spectrum extraction for redshifted 21-cm epoch of reionization experiments: the LOFAR case
• Non-parametric foreground subtraction for 21cm epoch of reionization experiments
• How well can we measure and understand foregrounds with 21 cm experiments?
• A 189 MHz, 2400 square degree polarization survey with the Murchison Widefield Array 32-element prototype
• Confirmation of Wide-Field Signatures in Redshifted 21 cm Power Spectra
• The Importance of Wide-field Foreground Removal for 21 cm Cosmology: A Demonstration With Early MWA Epoch of Reionization Observations
• Extending cosmological tests of General Relativity with the Square Kilometre Array
• Systematic Effects of Foreground Removal in 21cm Surveys of Reionization
• The Effects of Polarized Foregrounds on 21cm Epoch of Reionization Power Spectrum Measurements
• Effects of Antenna Beam Chromaticity on Redshifted 21~cm Power Spectrum and Implications for Hydrogen Epoch of Reionization Array
• Improved Measurement of the Spectral Index of the Diffuse Radio Background Between 90 and 190 MHz
• Complete history of the observable 21-cm signal from the first stars during the pre-reionization era
• Global 21cm signal experiments: A designer's guide
• The Murchison Widefield Array 21 cm Power Spectrum Analysis Methodology
• A Fast Method for Power Spectrum and Foreground Analysis for 21 cm Cosmology
• Spectral Line De-confusion in an Intensity Mapping Survey
• The EoR Sensitivity of the Murchison Widefield Array
• Constraining the epoch of reionization with the variance statistic: simulations of the LOFAR case
• Visibility based angular power spectrum estimation in low frequency radio interferometric observations
• Comparing Redundant and Sky Model Based Interferometric Calibration: A First Look with Phase II of the MWA
• Distinguishing models of reionization using future radio observations of 21-cm 1-point statistics
• Spherical Harmonic Analyses of Intensity Mapping Power Spectra
• GMRT observation towards detecting the Post-reionization 21-cm signal
• 21 cm observation of LSS at z~1 Instrument sensitivity and foreground subtraction
• Recovering the Wedge Modes Lost to 21-cm Foregrounds
• Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
• The visibility based Tapered Gridded Estimator (TGE) for the redshifted 21-cm power spectrum
• Adding Context to JWST Surveys with Current and Future 21cm Radio Observations
• Source counts and confusion at 72-231 MHz in the MWA GLEAM survey
• The AARTFAAC Cosmic Explorer: observations of the 21-cm power spectrum in the EDGES absorption trough
• Polarised foreground removal at low radio frequencies using rotation measure synthesis: uncovering the signature of hydrogen reionisation
• Subtraction of point sources from interferometric radio images through an algebraic forward modeling scheme
• Phase-Space Spectral Line De-confusion in Intensity Mapping
• Prospects of observing a quasar HII region during the Epoch of Reionization with redshifted 21cm
• The 21-cm Line as a Probe of Reionization
• Background reionization history from omniscopes
• Tapering the sky response for angular power spectrum estimation from low-frequency radio-interferometric data
• Prospects for detecting the 21cm forest from the diffuse intergalactic medium with LOFAR
• Detection of Signals from Cosmic Reionization using Radio Interferometric Signal Processing
• Bayesian semi-blind component separation for foreground removal in interferometric 21-cm observations
• 21-cm signature of the first sources in the Universe: Prospects of detection with SKA
• Contamination of the Epoch of Reionization power spectrum in the presence of foregrounds
• Joint estimation of the Epoch of Reionization power spectrum and foregrounds
• Low Frequency Imaging of Fields at High Galactic Latitude with the Murchison Widefield Array 32-Element Prototype
• Foreground modelling via Gaussian process regression: an application to HERA data
• Demonstrating the Tapered Gridded Estimator (TGE) for the Cosmological HI 21-cm Power Spectrum using $150\mathrm{MHz}$ GMRT observations
• Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization
• Prospects for detecting the 326.5 MHz redshifted 21 cm HI signal with the Ooty Radio Telescope (ORT)
• Violation of statistical isotropy and homogeneity in the 21-cm power spectrum
• Design of the New Wideband Vivaldi Feed for the HERA Radio-Telescope Phase II
• Exploring the Cosmic Reionization Epoch in Frequency Space: An Improved Approach to Remove the Foreground in 21 cm Tomography
• A Flux Scale for Southern Hemisphere 21cm EoR Experiments
• Detecting Cosmic Reionization using Bi-Spectrum Phase
• A Tapered Gridded Estimator (TGE) for the Multi-Frequency Angular Power Spectrum (MAPS) and the Cosmological HI 21-cm Power Spectrum
• The effect of baseline layouts on the EoR foreground wedge: a semi-analytical approach
• Assessing the impact of two independent direction-dependent calibration algorithms on the LOFAR 21-cm signal power spectrum
• Detecting the 21 cm Forest in the 21 cm Power Spectrum
• Exploring the evolution of Reionisation using a wavelet transform and the light cone effect
• Deep learning approach for identification of HII regions during reionization in 21-cm observations -- II. foreground contamination
• Statistical recovery of 21cm visibilities and their power spectra with Gaussian constrained realisations and Gibbs sampling
• Measuring HERA's primary beam in-situ: methodology and first results
• A Technique for Foreground Subtraction in Redshifted 21 cm Observations
• An Improved Statistical Point-Source Foreground Model for the Epoch of Reionization
• Cross-correlation of the HI 21-cm Signal and Lyman-alpha Forest: A Probe Of Cosmology
• A Bayesian analysis of redshifted 21-cm HI signal and foregrounds: Simulations for LOFAR
• Delay Spectrum with Phase-Tracking Arrays: Extracting the HI power spectrum from the Epoch of Reionization
• Primordial Non-Gaussianity and Reionization
• The Hydrogen Epoch of Reionization Array Dish III: Measuring Chromaticity of Prototype Element with Reflectometry
• Probing reionization with the cross power spectrum of 21 cm and near-infrared radiation backgrounds
• Observing the Reionization : Effect of Calibration and Position Errors on Realistic Observation Conditions
• Comparison of observing modes for statistical estimation of the 21cm signal from the Epoch of Reionisation
• A General Bayesian Framework to Account for Foreground Map Errors in Global 21-cm Experiments
• Measuring the Redshift of Reionization with a Modest Array of Low-Frequency Dipoles
• Measuring the cosmic expansion rate using 21-cm velocity acoustic oscillations
• Eliminating polarization leakage effect for neutral hydrogen intensity mapping with deep learning
• Statistical Detection of IGM Structures during Cosmic Reionization using Absorption of the Redshifted 21 cm line by HI against Compact Background Radio Sources
• Subtracting Foregrounds from Interferometric Measurements of the Redshifted 21 cm Emission
• Towards 21-cm Intensity Mapping at $z=2.28$ with uGMRT using the Tapered Gridded Estimator I: Foreground Avoidance
• Investigating the Contribution of Extended Radio Sources to the Epoch of Reionisation Power Spectrum
• Simulated foreground predictions for HI at z = 3.35 with the Ooty Wide Field Array: I. Instrument and the foregrounds
• The 21-cm Signal from the Cosmological Epoch of Recombination
• Measuring ultra-large scale effects in the presence of 21cm intensity mapping foregrounds
• SKA-Low Intensity Mapping Pathfinder Updates: Deeper 21 cm Power Spectrum Limits from Improved Analysis Frameworks
• Optimally Mapping Large-Scale Structures with Luminous Sources
• The first spectral line surveys searching for signals from the Dark Ages
• The precision and accuracy of early Epoch of Reionization foreground models: comparing MWA and PAPER 32-antenna source catalogs
• Detection of Cosmic Structures using the Bispectrum Phase. I. Mathematical Foundations
• An analytical method to simulate the HI 21-cm visibility signal for intensity mapping experiments
• The LOFAR EoR Data Model: (I) Effects of Noise and Instrumental Corruptions on the 21-cm Reionization Signal-Extraction Strategy
• Spectral modelling of Cygnus A between 110 and 250 MHz. Impact on the LOFAR 21-cm signal power spectrum
• Calibration requirements for Epoch of Reionization 21-cm signal observations -- II. Analytical estimation of the bias and variance with time-correlated residual gains
• Probing axion dark matter with 21cm fluctuations from minihalos
• Validating a novel angular power spectrum estimator using simulated low frequency radio-interferometric data
• Towards $21$-cm intensity mapping at $z=2.28$ with uGMRT using the tapered gridded estimator II: Cross-polarization power spectrum
• First upper limits on the 21-cm signal power spectrum of neutral hydrogen at $z=9.16$ from the LOFAR 3C196 field
• Clustering at 74 MHz
• The Tracking Tapered Gridded Estimator (TTGE) for the power spectrum from drift scan observations
• Towards Optimal Foreground Mitigation Strategies for Interferometric HI Intensity Mapping in the Low-Redshift Universe
• A Method to Extract the Angular Power Spectrum of the Epoch of Reionization from Low-Frequency Radio Interferometers
• The Effect of Interplanetary Scintillation on Epoch of Reionisation Power Spectra
• Influence of synchrotron self-absorption on the 21cm experiments
• Ionospheric effect on the synthetic Epoch of Reionization observations with the SKA1-Low
• Low-Frequency Radio Recombination Lines Away From the Inner Galactic Plane
• Reconstructing the Long-wavelength Matter Density Fluctuation Modes from the Scalar-Type Clustering Fossils
• FAST Drift Scan Survey for HI Intensity Mapping. II. Stacking-based Beam Construction of the 19-feed Array at $1.4$ GHz
• Cosmic Bandits: Exploration versus Exploitation in CMB B-Mode Experiments
• Primary Beam Chromaticity in HIRAX: I. Characterization from Simulations and Power Spectrum Implications
• Extracting the Epoch of Reionization Signal with 3D U-Net Neural Networks Using Data-driven Systematic Effect Model
• Luminosity Bias (II): The Cosmic Web of the First Stars
• Calibration requirement for Epoch of Reionization 21-cm signal observation -- III. Bias and variance in uGMRT ELAIS-N1 field power spectrum
• Blade Antenna-SDR System Prototype for the CANTAR Global 21-cm Experiment: Simulations, Measurements, and In-Situ Results
• Simulated differential observations of the Sunyaev-Zel'dovich Effect: Probing the Dark Ages and Epoch of Reionization
• Combined lensed estimator to probe the post reionization H I power spectrum
• Exploring delaying and heating effects on the 21-cm signature of fuzzy dark matter
• Cosmological 21cm experiments: Searching for a needle in a haystack
• Testing the growth of cosmic structures during the Dark Ages
• Direction-Dependent Polarised Primary Beams in Wide-Field Synthesis Imaging
• It's Always Darkest Before the Cosmic Dawn: Early Results from Novel Tools and Telescopes for 21 cm Cosmology
• The Correlation Calibration of PAPER-64 data
• The MWA Long Baseline Epoch of Reionisation Survey: I. Improved Source Catalogue for the EoR 0 field