Validating a novel angular power spectrum estimator using simulated low frequency radio-interferometric data

Abstract

The "Tapered Gridded Estimator" (TGE) is a novel way to directly estimate the angular power spectrum from radio-interferometric visibility data that reduces the computation by efficiently gridding the data, consistently removes the noise bias, and suppresses the foreground contamination to a large extent by tapering the primary beam response through an appropriate convolution in the visibility domain. Here we demonstrate the effectiveness of TGE in recovering the diffuse emission power spectrum through numerical simulations. We present details of the simulation used to generate low frequency visibility data for sky model with extragalactic compact radio sources and diffuse Galactic synchrotron emission. We then use different imaging strategies to identify the most effective option of point source subtraction and to study the underlying diffuse emission. Finally, we apply TGE to the residual data to measure the angular power spectrum, and assess the impact of incomplete point source subtraction in recovering the input power spectrum $C_{\ell }$ of the synchrotron emission. This estimator is found to successfully recovers the $C_{\ell }$ of input model from the residual visibility data. These results are relevant for measuring the diffuse emission like the Galactic synchrotron emission. It is also an important step towards characterizing and removing both diffuse and compact foreground emission in order to detect the redshifted $21\mathrm{cm}$ signal from the Epoch of Reionization.

18 pages, 1 table, 9 figures, Accepted for publication in New Astronomy

References in corpus (53)

• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Foreground Emission
• A multi-scale multi-frequency deconvolution algorithm for synthesis imaging in radio interferometry
• 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 method for subtracting foregrounds from multi-frequency CMB sky maps
• 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
• Foregrounds and Forecasts for the Cosmic Microwave Background
• Multifrequency analysis of 21 cm fluctuations from the Era of Reionization
• The Epoch of Reionization Window: I. Mathematical Formalism
• Foreground simulations for the LOFAR - Epoch of Reionization Experiment
• PAPER-64 Constraints on Reionization: The 21cm Power Spectrum at z=8.4
• Imaging the Epoch of Reionization: limitations from foreground confusion and imaging algorithms
• Radio Foregrounds for the 21cm Tomography of the Neutral Intergalactic Medium at High Redshifts
• The Epoch of Reionization Window: II. Statistical Methods for Foreground Wedge Reduction
• The impact of point source subtraction residuals on 21 cm Epoch of Reionization estimation
• The GMRT-EoR Experiment: A new upper limit on the neutral hydrogen power spectrum at z~8.6
• Foregrounds for observations of the cosmological 21 cm line: I. First Westerbork measurements of Galactic emission at 150 MHz in a low latitude field
• Foreground Contamination in Interferometric Measurements of the Redshifted 21 cm Power Spectrum
• Foreground Removal using FastICA: A Showcase of LOFAR-EoR
• A study of fundamental limitations to statistical detection of redshifted HI from the epoch of reionization
• Towards a model of full-sky Galactic synchrotron intensity and linear polarisation: a re-analysis of the Parkes data
• Realistic Simulations of the Galactic Polarized Foreground: Consequences for 21-cm Reionization Detection Experiments
• An Improved Method for 21cm Foreground Removal
• A Determination of the Spectral Index of Galactic Synchrotron Emission in the 1-10 GHz range
• Improving Foreground Subtraction in Statistical Observations of 21 cm Emission from the Epoch of Reionization
• CHIPS: The Cosmological HI Power Spectrum Estimator
• Foregrounds for redshifted 21 cm studies of reionization: GMRT 153 MHz observations
• Characterizing Foreground for redshifted 21-cm radiation: 150 MHz GMRT observations
• Power spectrum extraction for redshifted 21-cm epoch of reionization experiments: the LOFAR case
• Wide-field wide-band interferometric imaging:The WB A-Projection and hybrid algorithms
• Statistical Description of Synchrotron Intensity Fluctuations: Studies of Astrophysical Magnetic Turbulence
• How well can we measure and understand foregrounds with 21 cm experiments?
• Studying Galactic interstellar turbulence through fluctuations in synchrotron emission: First LOFAR Galactic foreground detection
• The Fundamental Multi-Baseline Mode-Mixing Foreground in 21 cm EoR Observations
• The Importance of Wide-field Foreground Removal for 21 cm Cosmology: A Demonstration With Early MWA Epoch of Reionization Observations
• Will point sources spoil 21 cm tomography?
• The Effects of Polarized Foregrounds on 21cm Epoch of Reionization Power Spectrum Measurements
• Parametrising Epoch of Reionization foregrounds: A deep survey of low-frequency point-source spectra with the MWA
• A Fast Method for Power Spectrum and Foreground Analysis for 21 cm Cosmology
• Visibility based angular power spectrum estimation in low frequency radio interferometric observations
• Spectral index properties of milliJansky radio sources
• The impact of Galactic synchrotron emission on CMB anisotropy measurements. I. Angular power spectrum analysis of total intensity all-sky surveys
• The visibility based Tapered Gridded Estimator (TGE) for the redshifted 21-cm power spectrum
• Probing magnetic turbulence by synchrotron polarimetry: statistics and structure of magnetic fields from Stokes correlators
• Tapering the sky response for angular power spectrum estimation from low-frequency radio-interferometric data
• Detection of Signals from Cosmic Reionization using Radio Interferometric Signal Processing
• Subtraction of Bright Point Sources from Synthesis Images of the Epoch of Reionization
• The angular power spectrum measurement of the Galactic synchrotron emission in two fields of the TGSS survey
• Subtracting Foregrounds from Interferometric Measurements of the Redshifted 21 cm Emission
• Reduced Ambiguity Calibration for LOFAR

Cited by in corpus (7)

• A Tapered Gridded Estimator (TGE) for the Multi-Frequency Angular Power Spectrum (MAPS) and the Cosmological HI 21-cm Power Spectrum
• Calibration Requirements for Epoch of Reionization 21-cm signal observations -- I. Effect of time-correlated gains
• A study of Kepler supernova remnant: angular power spectrum estimation from radio frequency data
• An Image-based Tapered Gridded Estimator (ITGE) for the angular power spectrum
• Calibration requirements for Epoch of Reionization 21-cm signal observations -- II. Analytical estimation of the bias and variance with time-correlated residual gains
• Calibration requirement for Epoch of Reionization 21-cm signal observation -- III. Bias and variance in uGMRT ELAIS-N1 field power spectrum
• Using strong gravitational lensing to probe the post reionization \HI power spectrum