The impact of lunar topography on the 21-cm power spectrum for grid-based arrays : Insights for the Dark-ages EXplorer (DEX)

Abstract

The Dark Ages (DA) provides a crucial window into the physics of the infant Universe, with the 21-cm signal offering the only direct probe for mapping out the three-dimensional distribution of matter at this epoch. To measure this cosmological signal, the Dark-ages EXplorer (DEX) has been proposed as a compact, grid-based radio array on the lunar farside. The minimal design consists of a 32 $\times$ 32 array of 3-m dipole antennas, operating in the $7-50$ MHz band. A practical challenge on the lunar surface is that the antennas may get displaced from their intended positions due to deployment imprecisions and non-coplanarity arising from local surface undulations. We present, for the first time, an end-to-end simulation pipeline, called SPADE-21cm, that integrates a sky model with a DA 21-cm signal model simulated in the lunar frame and incorporating lunar topography data. We study the effects of both lateral (xy) and vertical (z) offsets on the two-dimensional power spectra across the $7-12$ MHz and $30-35$ MHz spectral windows, with tolerance thresholds derived only for the latter. Our results show that positional offsets bias the power spectrum by $10-30$ per cent relative to the expected 21-cm power spectrum during DA. Lateral offsets within ${\sigma }_{xy}/\lambda \lesssim 0.027$ (at 32.5 MHz) keep the fraction of Fourier modes with strong contamination (> 50 per cent of the signal) to less than 1 per cent, whereas vertical height offsets affect a larger fraction. This conclusion holds for the 21-cm window with $k_{\parallel }>0.5$ $h$ cMpc${}^{-1}$ over the range of $k_{\perp }=0.003-0.009$ $h$ cMpc${}^{-1}$.

arXiv comment27 pages, 12 figures, Under review in MNRAS. Comments are welcome!

References in corpus (116)

• SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• Planck 2015 results. XIII. Cosmological parameters
• The Astropy Project: Building an inclusive, open-science project and status of the v2.0 core package
• HEALPix -- a Framework for High Resolution Discretization, and Fast Analysis of Data Distributed on the Sphere
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• The James Webb Space Telescope
• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• An absorption profile centred at 78 megahertz in the sky-averaged spectrum
• CASA, the Common Astronomy Software Applications for Radio Astronomy
• WSClean: an implementation of a fast, generic wide-field imager for radio astronomy
• 21cmFAST: A Fast, Semi-Numerical Simulation of the High-Redshift 21-cm Signal
• A model of diffuse Galactic Radio Emission from 10 MHz to 100 GHz
• Indirect Dark Matter Signatures in the Cosmic Dark Ages I. Generalizing the Bound on s-wave Dark Matter Annihilation from Planck
• Cosmological Parameter Estimation Using 21 cm Radiation from the Epoch of Reionization
• Reionization and the Cosmic Dawn with the Square Kilometre Array
• Four Fundamental Foreground Power Spectrum Shapes for 21 cm Cosmology Observations
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• Detecting the Earliest Galaxies Through Two New Sources of 21cm Fluctuations
• 21 cm fluctuations from inhomogeneous X-ray heating before reionization
• Identification and properties of intense star-forming galaxies at redshifts z>10
• Revisiting the radio interferometer measurement equation. I. A full-sky Jones formalism
• Toward Epoch of Reionization Measurements with Wide-Field Radio Observations
• Indirect Dark Matter Signatures in the Cosmic Dark Ages II. Ionization, Heating and Photon Production from Arbitrary Energy Injections
• Data Analysis for Precision 21 cm Cosmology
• 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
• Calibration Requirements for Detecting the 21 cm Epoch of Reionization Power Spectrum and Implications for the SKA
• Constraining the unexplored period between reionization and the dark ages with observations of the global 21 cm signal
• First Season MWA EoR Power Spectrum Results at Redshift 7
• The low-frequency environment of the Murchison Widefield Array: radio-frequency interference analysis and mitigation
• The Cosmic Dawn and Epoch of Reionization with the Square Kilometre Array
• Energy Injection And Absorption In The Cosmic Dark Ages
• The Fast Fourier Transform Telescope
• 21cm Limits on Decaying Dark Matter and Primordial Black Holes
• Observing Neutral Hydrogen Above Redshift 6: The "Global" Perspective
• Probing the First Stars and Black Holes in the Early Universe with the Dark Ages Radio Explorer (DARE)
• Probing Ionospheric Structures using the LOFAR radio telescope
• A Ground Plane Artifact that Induces an Absorption Profile in Averaged Spectra from Global 21-cm Measurements - with Possible Application to EDGES
• The Sensitivity of First Generation Epoch of Reionization Observatories and Their Potential for Differentiating Theoretical Power Spectra
• The Impact of the First Galaxies on Cosmic Dawn and Reionization
• Prospects for Cosmological Collider Physics
• First Batch of Candidate Galaxies at Redshifts 11 to 20 Revealed by the James Webb Space Telescope Early Release Observations
• The Effects of Dark Matter-Baryon Scattering on Redshifted 21 cm Signals
• Primordial non-gaussianity from the bispectrum of 21-cm fluctuations in the dark ages
• The Impact of Modeling Errors on Interferometer Calibration for 21 cm Power Spectra
• 21-cm Background Anisotropies Can Discern Primordial Non-Gaussianity
• The LWA1 Low Frequency Sky Survey
• Fundamental Limitations on the Calibration of Redundant 21 cm Cosmology Instruments and Implications for HERA and the SKA
• Distributed Radio Interferometric Calibration
• Large-Scale Structure and Gravitational Waves III: Tidal Effects
• Omniscopes: Large Area Telescope Arrays with only N log N Computational Cost
• The Effects of Polarized Foregrounds on 21cm Epoch of Reionization Power Spectrum Measurements
• 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
• Mitigating the Effects of Antenna-to-Antenna Variation on Redundant-Baseline Calibration for 21 cm Cosmology
• Unintended electromagnetic radiation from Starlink satellites detected with LOFAR between 110 and 188 MHz
• Lensing of 21-cm Fluctuations by Primordial Gravitational Waves
• The impact of interference excision on 21-cm Epoch of Reionization power spectrum analyses
• First upper limits on the 21 cm signal power spectrum from cosmic dawn from one night of observations with NenuFAR
• Discovering the Sky at the Longest wavelengths with a lunar orbit array
• Quantifying Ionospheric Effects on Global 21-cm Observations
• The FHD/$\mathbf{\epsilon }$ppsilon Epoch of Reionization Power Spectrum Pipeline
• Can Early Dark Energy Explain EDGES?
• Scintillation noise power spectrum and its impact on high redshift 21-cm observations
• Validation of EDGES Low-Band Antenna Beam Model
• The Hydrogen Epoch of Reionization Array Dish II: Characterization of Spectral Structure with Electromagnetic Simulations and its science Implications
• Prospects for precision cosmology with the 21 cm signal from the dark ages
• The Bias and Uncertainty of Redundant and Sky-Based Calibration under Realistic Sky and Telescope Conditions
• Two- and Three-Dimensional Probes of Parity in Primordial Gravity Waves
• Polarization leakage in epoch of reionization windows: II. Primary beam model and direction dependent calibration
• Polarization leakage in epoch of reionization windows: III. Wide-field effects of narrow-field arrays
• Patterns of primary beam non-redundancy in close-packed 21 cm array observations
• Constraining Polarized Foregrounds for EoR Experiments I: 2D Power Spectra from the PAPER-32 Imaging Array
• Antenna beam characterisation for the global 21cm experiment LEDA and its impact on signal model parameter reconstruction
• Array Element Coupling in Radio Interferometry I: A Semi-Analytic Approach
• An Ultra-long Wavelength Sky Model with Absorption Effect
• PRATUSH experiment concept and design overview
• Detection of intended and unintended emissions from Starlink satellites in the SKA-Low frequency range, at the SKA-Low site, with an SKA-Low station analog
• Characterizing the Radio Quiet Region Behind the Lunar Farside for Low Radio Frequency Experiments
• A Digital-Receiver for the Murchison Widefield Array
• Ionospheric Power-Spectrum Tomography in Radio Interferometry
• The impact of the ionosphere on ground-based detection of the global Epoch of Reionisation signal
• The All-Sky SignAl Short-Spacing INterferometer (ASSASSIN) I: Global sky measurements with the Engineering Development Array-2
• The Impact of Beam Variations on Power Spectrum Estimation for 21-cm Cosmology I: Simulations of Foreground Contamination for HERA
• Statistical analysis of the causes of excess variance in the 21 cm signal power spectra obtained with the Low-Frequency Array
• The Dark Ages' 21-cm Trispectrum
• Enabling Next Generation Dark Energy and Epoch of Reionization Radio Observatories with the MOFF Correlator
• Large-scale Array for Radio Astronomy on the Farside
• 21cmFirstCLASS I. Cosmological tool for $\Lambda$CDM and beyond
• A Real-Time, All-Sky, High Time Resolution, Direct Imager for the Long Wavelength Array
• The brightness and spatial distributions of terrestrial radio sources
• Simulating the Detection of the Global 21 cm Signal with MIST for Different Models of the Soil and Beam Directivity
• Constraining exotic dark matter models with the dark ages 21-cm signal
• Beyond the horizon: Quantifying the full sky foreground wedge in the cylindrical power spectrum
• Sensitivity of the Hydrogen Epoch of Reionization Array and its Build-out Stages to One-point Statistics from Redshifted 21 cm Observations
• Enlightening the dark ages with dark matter
• The Role of the Instrumental Response in 21 cm EoR Power Spectrum Gridding Analyses
• Impacts of new small-scale N-body simulations on dark matter annihilations constrained from cosmological 21cm line observations
• Ultra-Low-Frequency Radio Astronomy Observations from a Selenocentric Orbit: first results of the Longjiang-2 experiment
• Transient RFI environment of LOFAR-LBA at 72-75 MHz: Impact on ultra-widefield AARTFAAC Cosmic Explorer observations of the redshifted 21-cm signal
• Impact of radiation from primordial black holes on the 21-cm angular-power spectrum in the dark ages
• 21cmFirstCLASS II. Early linear fluctuations of the 21cm signal
• Near-field imaging of local interference in radio interferometric data: Impact on the redshifted 21 cm power spectrum
• Ground Experiments and Performance Evaluation of the Low-Frequency Radio Spectrometer Onboard the Lander of Chang'e-4 Mission
• `First Light' in the Universe; What Ended the "Dark Age"?
• Optimization and Commissioning of the EPIC Commensal Radio Transient Imager for the Long Wavelength Array
• Lunar Far-Side Radio Arrays: A Preliminary Site Survey
• Broadband Polarized Radio Emission Detected from Starlink Satellites Below 100 MHz with NenuFAR
• Understanding spectral artefacts in SKA-LOW 21-cm cosmology experiments: the impact of cable reflections
• Robust direction-dependent gain-calibration of beam-modelling errors far from the target field
• Estimating Soil Electrical Parameters in the Canadian High Arctic from Impedance Measurements of the MIST Antenna Above the Surface
• Comparison of Fast, Hybrid Imaging Architectures for Multi-scale, Hierarchical Aperture Arrays