Simulations of primary beam effects on the cosmic bispectrum phase observed with the Hydrogen Epoch of Reionization Array

Abstract

The 21~cm transition from neutral Hydrogen promises to be the best observational probe of the Epoch of Reionisation. The main difficulty in measuring the 21 cm signal is the presence of bright foregrounds that require very accurate interferometric calibration. Closure quantities may circumvent the calibration requirements but may be, however, affected by direction dependent effects, particularly antenna primary beam responses. This work investigates the impact of antenna primary beams affected by mutual coupling on the closure phase and its power spectrum. Our simulations show that primary beams affected by mutual coupling lead to a leakage of foreground power into the EoR window, which can be up to $\sim 4$ orders magnitude higher than the case where no mutual coupling is considered. This leakage is, however, essentially confined at $k<0.3$~$h$~Mpc${}^{-1}$ for triads that include 29~m baselines. The leakage magnitude is more pronounced when bright foregrounds appear in the antenna sidelobes, as expected. Finally, we find that triads that include mutual coupling beams different from each other have power spectra similar to triads that include the same type of mutual coupling beam, indicating that beam-to-beam variation within triads (or visibility pairs) is not the major source of foreground leakage in the EoR window.

References in corpus (13)

• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• Revisiting the radio interferometer measurement equation. I. A full-sky Jones formalism
• HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization
• The Effects of Dark Matter Decay and Annihilation on the High-Redshift 21 cm Background
• Modelling of the Spectral Energy Distribution of Fornax A: Leptonic and Hadronic Production of High Energy Emission from the Radio Lobes
• Spherical Harmonic Analyses of Intensity Mapping Power Spectra
• Mapmaking for Precision 21 cm Cosmology
• Absolute Calibration Strategies for the Hydrogen Epoch of Reionization Array and Their Impact on the 21 cm Power Spectrum
• Contamination of the Epoch of Reionization power spectrum in the presence of foregrounds
• A high resolution foreground model for the MWA EoR1 field: model and implications for EoR power spectrum analysis
• Foreground modelling via Gaussian process regression: an application to HERA data
• Detection of Cosmic Structures using the Bispectrum Phase. II. First Results from Application to Cosmic Reionization Using the Hydrogen Epoch of Reionization Array
• Detection of Cosmic Structures using the Bispectrum Phase. I. Mathematical Foundations

Cited by in corpus (3)

• On the use of temporal filtering for mitigating galactic synchrotron calibration bias in 21 cm reionization observations
• Strategy for mitigation of systematics for EoR experiments with the Murchison Widefield Array
• Establishing a relationship between the cosmological 21 cm power spectrum and interferometric closure phases