Constraining Polarized Foregrounds for EOR Experiments II: Polarization Leakage Simulations in the Avoidance Scheme

Abstract

A critical challenge in the observation of the redshifted 21-cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday rotation as they propagate through the interstellar medium, may harmfully contaminate the 21-cm power spectrum. We develop a formalism to describe the leakage due to instrumental widefield effects in visibility-based power spectra measured with redundant arrays, extending the delay-spectrum approach presented in Parsons et al. (2012). We construct polarized sky models and propagate them through the instrument model to simulate realistic full-sky observations with the Precision Array to Probe the Epoch of Reionization. We find that the leakage due to a population of polarized point sources is expected to be higher than diffuse Galactic polarization at any $k$ mode for a 30~m reference baseline. For the same reference baseline, a foreground-free window at $k>0.3h$~Mpc${}^{-1}$ can be defined in terms of leakage from diffuse Galactic polarization even under the most pessimistic assumptions. If measurements of polarized foreground power spectra or a model of polarized foregrounds are given, our method is able to predict the polarization leakage in actual 21-cm observations, potentially enabling its statistical subtraction from the measured 21-cm power spectrum.

11 pages, 10 figures, ApJ accepted

References in corpus (68)

• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• Faraday Rotation Measure Synthesis
• Hydrogen Epoch of Reionization Array (HERA)
• The Precision Array for Probing the Epoch of Reionization: 8 Station Results
• 21 Centimeter Fluctuations from Cosmic Gas at High Redshifts
• Bright Source Subtraction Requirements For Redshifted 21 cm Measurements
• The Evolution of the Intergalactic Medium
• A Per-Baseline, Delay-Spectrum Technique for Accessing the 21cm Cosmic Reionization Signature
• Four Fundamental Foreground Power Spectrum Shapes for 21 cm Cosmology Observations
• Upper limits on the 21-cm Epoch of Reionization power spectrum from one night with LOFAR
• The Epoch of Reionization Window: I. Mathematical Formalism
• New Limits on 21cm EoR From PAPER-32 Consistent with an X-Ray Heated IGM at z=7.7
• Foreground simulations for the LOFAR - Epoch of Reionization Experiment
• Revisiting the radio interferometer measurement equation. I. A full-sky Jones formalism
• PAPER-64 Constraints on Reionization: The 21cm Power Spectrum at z=8.4
• The Epoch of Reionization Window: II. Statistical Methods for Foreground Wedge Reduction
• A lower limit of dz > 0.06 for the duration of the reionization epoch
• Overcoming real-world obstacles in 21 cm power spectrum estimation: A method demonstration and results from early Murchison Widefield Array data
• Foregrounds for observations of the cosmological 21 cm line: I. First Westerbork measurements of Galactic emission at 150 MHz in a low latitude field
• Opening the 21cm EoR Window: Measurements of Foreground Isolation with PAPER
• Radio polarization from the inner Galaxy at arcminute resolution
• First Season MWA EoR Power Spectrum Results at Redshift 7
• Detecting the Rise and Fall of 21 cm Fluctuations with the Murchison Widefield Array
• Low-Mach-number turbulence in interstellar gas revealed by radio polarization gradients
• A study of fundamental limitations to statistical detection of redshifted HI from the epoch of reionization
• Correcting direction-dependent gains in the deconvolution of radio interferometric images
• Realistic Simulations of the Galactic Polarized Foreground: Consequences for 21-cm Reionization Detection Experiments
• CHIPS: The Cosmological HI Power Spectrum Estimator
• Empirical Covariance Modeling for 21 cm Power Spectrum Estimation: A Method Demonstration and New Limits from Early Murchison Widefield Array 128-Tile Data
• Bayesian constraints on the global 21-cm signal from the Cosmic Dawn
• Foregrounds for observations of the cosmological 21 cm line: II. Westerbork observations of the fields around 3C196 and the North Celestial Pole
• First Limits on the 21 cm Power Spectrum during the Epoch of X-ray heating
• Fast Holographic Deconvolution: a new technique for precision radio interferometry
• Applying full polarization A-Projection to very wide field of view instruments: An imager for LOFAR
• The nature of the low-frequency emission of M51: First observations of a nearby galaxy with LOFAR
• 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
• Calibration of Low-Frequency, Wide-Field Radio Interferometers Using Delay/Delay-Rate Filtering
• Linear polarization structures in LOFAR observations of the interstellar medium in the 3C196 field
• PAPER-64 Constraints On Reionization II: The Temperature Of The z=8.4 Intergalactic Medium
• Multi-redshift limits on the 21cm power spectrum from PAPER
• Initial LOFAR observations of Epoch of Reionization windows: II. Diffuse polarized emission in the ELAIS-N1 field
• Low frequency observations of linearly polarized structures in the interstellar medium near the south Galactic pole
• 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
• Fast simulations for intensity mapping experiments
• The Murchison Widefield Array Commissioning Survey: A Low-Frequency Catalogue of 14,110 Compact Radio Sources over 6,100 Square Degrees
• WSRT Faraday tomography of the Galactic ISM at λ~ 0.86 m
• Characteristics of the structure in the Galactic polarized radio background at 350 MHz
• Interferometric imaging with the 32 element Murchison Wide-field Array
• Imaging neutral hydrogen on large-scales during the Epoch of Reionization with LOFAR
• High Galactic latitude polarized emission at 1.4 GHz and implications for cosmic microwave background observations
• Software Holography: Interferometric Data Analysis for the Challenges of Next Generation Observatories
• 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
• Polarization leakage in epoch of reionization windows: II. Primary beam model and direction dependent calibration
• Rotation measure synthesis at the 2 m wavelength of the FAN region: Unveiling screens and bubbles
• The angular power spectra of polarized Galactic synchrotron
• Constraints on the temperature of the intergalactic medium at z=8.4 with 21-cm observations
• Constraining Polarized Foregrounds for EoR Experiments I: 2D Power Spectra from the PAPER-32 Imaging Array
• Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization
• A Flux Scale for Southern Hemisphere 21cm EoR Experiments
• Polarization observations in a low synchrotron emission field at 1.4 GHz
• The Parkes Galactic Meridian Survey (PGMS): observations and CMB polarization foreground analysis
• Intrinsic Instrumental Polarization and High-Precision Pulsar Timing
• Imaging on PAPER: Centaurus A at 148 MHz
• An angular power spectrum analysis of the DRAO 1.4 GHz polarization survey: implications for CMB observations

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