Aliasing from Galactic Plane Setting in Widefield Radio Interferometry

Abstract

Measurements with widefield radio interferometers often include the near-infinite gradient between the sky and the horizon. This causes aliasing inherent to the measurement itself, and is purely a consequence of the Fourier basis. For this reason, the horizon is often attenuated by the instrumental beam down to levels deemed inconsequential. However, this effect is enhanced via our own Galactic plane as it sets over the course of a night. We show all-sky simulations of the Galactic plane setting in a radio interferometer in detail for the first time. We then apply these simulations to the Murchison Widefield Array to show that a beam attenuation of 0.1% is not sufficient in some precision science cases. We determine that the noise statistics of the residual data image are drastically more Gaussian with aliasing removal, and explore consequences in simulation for cataloging of extragalactic sources and 21 cm Epoch of Reionization detection via the power spectrum.

arXiv comment10 pages, 3 figures, published in ApJ

References in corpus (37)

• LOFAR: The LOw-Frequency ARray
• The Murchison Widefield Array: the Square Kilometre Array Precursor at low radio frequencies
• Hydrogen Epoch of Reionization Array (HERA)
• An Accurate Flux Density Scale from 50 MHz to 50 GHz
• Bright Source Subtraction Requirements For Redshifted 21 cm Measurements
• A Per-Baseline, Delay-Spectrum Technique for Accessing the 21cm Cosmic Reionization Signature
• Four Fundamental Foreground Power Spectrum Shapes for 21 cm Cosmology Observations
• The Epoch of Reionization Window: I. Mathematical Formalism
• LOFAR 150-MHz observations of the Boötes field: Catalogue and Source Counts
• Toward Epoch of Reionization Measurements with Wide-Field Radio Observations
• Imaging the Epoch of Reionization: limitations from foreground confusion and imaging algorithms
• The impact of point source subtraction residuals on 21 cm Epoch of Reionization estimation
• Calibration Requirements for Detecting the 21 cm Epoch of Reionization Power Spectrum and Implications for the SKA
• Opening the 21cm EoR Window: Measurements of Foreground Isolation with PAPER
• A study of fundamental limitations to statistical detection of redshifted HI from the epoch of reionization
• Improving the Epoch of Reionization Power Spectrum Results from Murchison Widefield Array Season 1 Observations
• A Size of ~10 Mpc for the Ionized Bubbles at the End of Cosmic Reionization
• Systematic biases in low frequency radio interferometric data due to calibration: the LOFAR EoR case
• Fast Holographic Deconvolution: a new technique for precision radio interferometry
• First Season MWA Phase II EoR Power Spectrum Results at Redshift 7
• The Fundamental Multi-Baseline Mode-Mixing Foreground in 21 cm EoR Observations
• 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
• The Distribution of Bubble Sizes During Reionization
• The impact of interference excision on 21-cm Epoch of Reionization power spectrum analyses
• The FHD/$\mathbf{\epsilon }$ppsilon Epoch of Reionization Power Spectrum Pipeline
• The impact of spin temperature fluctuations on the 21-cm moments
• Source counts and confusion at 72-231 MHz in the MWA GLEAM survey
• Radio Source Extraction with ProFound
• Lost Horizon: Quantifying the Effect of Local Topography on Global 21-cm Cosmology Data Analysis
• A Map of Diffuse Radio Emission at 182 MHz to Enhance Epoch of Reionization Observations in the Southern Hemisphere
• On the use of temporal filtering for mitigating galactic synchrotron calibration bias in 21 cm reionization observations
• The Role of the Instrumental Response in 21 cm EoR Power Spectrum Gridding Analyses
• Investigating the Contribution of Extended Radio Sources to the Epoch of Reionisation Power Spectrum
• Measurements of one-point statistics in 21 cm intensity maps via foreground avoidance strategy
• Skew spectrum and smoothed skewness of 21-cm signals from epoch of reionization
• The Impact of ionization Morphology and X-ray Heating on the Cosmological 21cm Skew Spectrum

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• Diffuse radio sky models using large scale shapelets