Absolute Calibration Strategies for the Hydrogen Epoch of Reionization Array and Their Impact on the 21 cm Power Spectrum

Abstract

We discuss absolute calibration strategies for Phase I of the Hydrogen Epoch of Reionization Array (HERA), which aims to measure the cosmological 21 cm signal from the Epoch of Reionization (EoR). HERA is a drift-scan array with a 10 degree wide field of view, meaning bright, well-characterized point source transits are scarce. This, combined with HERA's redundant sampling of the uv plane and the modest angular resolution of the Phase I instrument, make traditional sky-based and self-calibration techniques difficult to implement with high dynamic range. Nonetheless, in this work we demonstrate calibration for HERA using point source catalogues and electromagnetic simulations of its primary beam. We show that unmodeled diffuse flux and instrumental contaminants can corrupt the gain solutions, and present a gain smoothing approach for mitigating their impact on the 21 cm power spectrum. We also demonstrate a hybrid sky and redundant calibration scheme and compare it to pure sky-based calibration, showing only a marginal improvement to the gain solutions at intermediate delay scales. Our work suggests that the HERA Phase I system can be well-calibrated for a foreground-avoidance power spectrum estimator by applying direction-independent gains with a small set of degrees of freedom across the frequency and time axes.

arXiv commentAccepted to ApJ

References in corpus (72)

• Astropy: A Community Python Package for Astronomy
• Planck 2015 results. XIII. Cosmological parameters
• LOFAR: The LOw-Frequency ARray
• The Murchison Widefield Array: the Square Kilometre Array Precursor at low radio frequencies
• An absorption profile centred at 78 megahertz in the sky-averaged spectrum
• The GMRT 150 MHz All-sky Radio Survey: First Alternative Data Release TGSS ADR1
• Hydrogen Epoch of Reionization Array (HERA)
• GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey I: A low-frequency extragalactic catalogue
• A model of diffuse Galactic Radio Emission from 10 MHz to 100 GHz
• Reionization and Cosmology with 21 cm Fluctuations
• The Precision Array for Probing the Epoch of Reionization: 8 Station Results
• Ionospheric Calibration of Low Frequency Radio Interferometric Observations using the Peeling Scheme: I. Method Description and First Results
• Bright Source Subtraction Requirements For Redshifted 21 cm Measurements
• A simulation calibrated limit on the HI power spectrum from the GMRT Epoch of Reionization experiment
• A Per-Baseline, Delay-Spectrum Technique for Accessing the 21cm Cosmic Reionization Signature
• The non-coplanar baselines effect in radio interferometry: The W-Projection algorithm
• 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
• The Very Large Array Low-frequency Sky Survey Redux (VLSSr)
• A Sensitivity and Array-Configuration Study for Measuring the Power Spectrum of 21cm Emission from Reionization
• An Improved Model of Diffuse Galactic Radio Emission from 10 MHz to 5 THz
• Overcoming real-world obstacles in 21 cm power spectrum estimation: A method demonstration and results from early Murchison Widefield Array data
• 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
• 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
• Correcting direction-dependent gains in the deconvolution of radio interferometric images
• Foregrounds in Wide-Field Redshifted 21 cm Power Spectra
• A simplified, lossless re-analysis of PAPER-64
• Improving the Epoch of Reionization Power Spectrum Results from Murchison Widefield Array Season 1 Observations
• Precision Calibration of Radio Interferometers Using Redundant Baselines
• Bayesian constraints on the global 21-cm signal from the Cosmic Dawn
• The 21 cm Power Spectrum from the Cosmic Dawn: First Results from the OVRO-LWA
• The Impact of Modeling Errors on Interferometer Calibration for 21 cm Power Spectra
• The first power spectrum limit on the 21-cm signal of neutral hydrogen during the Cosmic Dawn at z=20-25 from LOFAR
• 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
• A 189 MHz, 2400 square degree polarization survey with the Murchison Widefield Array 32-element prototype
• Fundamental Limitations on the Calibration of Redundant 21 cm Cosmology Instruments and Implications for HERA and the SKA
• MITEoR: A Scalable Interferometer for Precision 21 cm Cosmology
• Multi-redshift limits on the 21cm power spectrum from PAPER
• The Radio Sky at Meter Wavelengths: m-Mode Analysis Imaging with the Owens Valley Long Wavelength Array
• Effects of Antenna Beam Chromaticity on Redshifted 21~cm Power Spectrum and Implications for Hydrogen Epoch of Reionization Array
• Mitigating Internal Instrument Coupling for 21 cm Cosmology I: Temporal and Spectral Modeling in Simulations
• Mitigating Internal Instrument Coupling II: A Method Demonstration with the Hydrogen Epoch of Reionization Array
• Redundant Array Configurations for 21 cm Cosmology
• Characterizing Signal Loss in the 21 cm Reionization Power Spectrum: A Revised Study of PAPER-64
• The challenges of low-frequency radio polarimetry: lessons from the Murchison Widefield Array
• Mitigating the Effects of Antenna-to-Antenna Variation on Redundant-Baseline Calibration for 21 cm Cosmology
• Understanding the Diversity of 21 cm Cosmology Analyses
• The Hydrogen Epoch of Reionization Array Dish I: Beam Pattern Measurements and Science Implications
• Comparing Redundant and Sky Model Based Interferometric Calibration: A First Look with Phase II of the MWA
• Modelling of the Spectral Energy Distribution of Fornax A: Leptonic and Hadronic Production of High Energy Emission from the Radio Lobes
• The FHD/$\mathbf{\epsilon }$ppsilon Epoch of Reionization Power Spectrum Pipeline
• HI 21cm Cosmology and the Bi-spectrum: Closure Diagnostics in Massively Redundant Interferometric Arrays
• Polarized Redundant-Baseline Calibration for 21 cm Cosmology Without Adding Spectral Structure
• Optimized Beam Sculpting with Generalized Fringe-Rate Filters
• The Hydrogen Epoch of Reionization Array Dish II: Characterization of Spectral Structure with Electromagnetic Simulations and its science Implications
• A Technique for Primary Beam Calibration of Drift-Scanning, Wide-Field Antenna Elements
• The Bias and Uncertainty of Redundant and Sky-Based Calibration under Realistic Sky and Telescope Conditions
• Improved 21 cm Epoch Of Reionization Power Spectrum Measurements with a Hybrid Foreground Subtraction and Avoidance Technique
• Wide-field LOFAR-LBA power-spectra analyses: Impact of calibration, polarization leakage and ionosphere
• Constraining Polarized Foregrounds for EoR Experiments I: 2D Power Spectra from the PAPER-32 Imaging Array
• New Limits on Polarized Power Spectra at 126 and 164 MHz: Relevance to Epoch of Reionization Measurements
• Constraining Polarized Foregrounds for EOR Experiments II: Polarization Leakage Simulations in the Avoidance Scheme
• A Flux Scale for Southern Hemisphere 21cm EoR Experiments
• The HERA-19 Commissioning Array: Direction Dependent Effects
• Fundamental uncertainty levels of 21cm power spectra from a delay analysis
• The Hydrogen Epoch of Reionization Array Dish III: Measuring Chromaticity of Prototype Element with Reflectometry
• Ionospheric Attenuation of Polarized Foregrounds in 21 cm Epoch of Reionization Measurements: A Demonstration for the HERA Experiment

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• First Results from HERA Phase I: Upper Limits on the Epoch of Reionization 21 cm Power Spectrum
• Improved Constraints on the 21 cm EoR Power Spectrum and the X-Ray Heating of the IGM with HERA Phase I Observations
• HERA Phase I Limits on the Cosmic 21-cm Signal: Constraints on Astrophysics and Cosmology During the Epoch of Reionization
• Redundant-Baseline Calibration of the Hydrogen Epoch of Reionization Array
• Gaussian Process Foreground Subtraction and Power Spectrum Estimation for 21 cm Cosmology
• A 21-cm power spectrum at 48 MHz, using the Owens Valley Long Wavelength Array
• Understanding the HERA Phase I receiver system with simulations and its impact on the detectability of the EoR delay power spectrum
• A Unified Calibration Framework for 21 cm Cosmology
• Patterns of primary beam non-redundancy in close-packed 21 cm array observations
• Hydrogen Epoch of Reionization Array (HERA) Phase II Deployment and Commissioning
• Foreground modelling via Gaussian process regression: an application to HERA data
• Quantifying Excess Power from Radio Frequency Interference in Epoch of Reionization Measurements
• Validation of the HERA Phase I Epoch of Reionization 21 cm Power Spectrum Software Pipeline
• Design of the New Wideband Vivaldi Feed for the HERA Radio-Telescope Phase II
• Detection of Cosmic Structures using the Bispectrum Phase. II. First Results from Application to Cosmic Reionization Using the Hydrogen Epoch of Reionization Array
• Measuring HERA's primary beam in-situ: methodology and first results
• The Impact of Beam Variations on Power Spectrum Estimation for 21-cm Cosmology I: Simulations of Foreground Contamination for HERA
• Methods of Error Estimation for Delay Power Spectra in $21\text{cm}$ Cosmology
• Observing the Reionization : Effect of Calibration and Position Errors on Realistic Observation Conditions
• A Bayesian approach to high fidelity interferometric calibration II: demonstration with simulated data
• On the use of temporal filtering for mitigating galactic synchrotron calibration bias in 21 cm reionization observations
• Impact of instrument and data characteristics in the interferometric reconstruction of the 21 cm power spectrum
• Post-reionization HI 21-cm signal: A probe of negative cosmological constant
• Direct Optimal Mapping for 21cm Cosmology: A Demonstration with the Hydrogen Epoch of Reionization Array
• Effects of model incompleteness on the drift-scan calibration of radio telescopes
• Spectral modelling of Cygnus A between 110 and 250 MHz. Impact on the LOFAR 21-cm signal power spectrum
• Delay-Weighted Calibration: Precision Calibration for 21 cm Cosmology with Resilience to Sky Model Error
• A Differentiable, End-to-End Forward Model for 21 cm Cosmology: Estimating the Foreground, Instrument, and Signal Joint Posterior
• Probing the Epoch of Reionization using synergies of line intensity mapping
• Automated Detection of Antenna Malfunctions in Large-N Interferometers: A Case Study with the Hydrogen Epoch of Reionization Array
• Simulations of primary beam effects on the cosmic bispectrum phase observed with the Hydrogen Epoch of Reionization Array
• Calibration Schemes with $\mathcal{O}(N\log N)$ Scaling for Large-N Radio Interferometers Built on a Regular Grid
• Exploring One-point Statistics in HERA Phase I Data: Effects of Foregrounds and Systematics on Measuring One-Point Statistics
• A Bayesian approach to high fidelity interferometric calibration I: mathematical formalism
• Removing systematics-induced 21-cm foreground residuals by cross-correlating filtered data
• Imaging and Modeling Data from the Hydrogen Epoch of Reionization Array
• A Real Time Processing System for Big Data in Astronomy: Applications to HERA