Demonstrating the Tapered Gridded Estimator (TGE) for the Cosmological HI 21-cm Power Spectrum using $150\mathrm{MHz}$ GMRT observations

Abstract

We apply the Tapered Gridded Estimator (TGE) for estimating the cosmological 21-cm power spectrum from $150\mathrm{MHz}$ GMRT observations which corresponds to the neutral hydrogen (HI) at redshift $z=8.28$. Here TGE is used to measure the Multi-frequency Angular Power Spectrum (MAPS) $C_{\ell }(\Delta \nu )$ first, from which we estimate the 21-cm power spectrum $P(k_{\perp },k_{\parallel })$. The data here are much too small for a detection, and the aim is to demonstrate the capabilities of the estimator. We find that the estimated power spectrum is consistent with the expected foreground and noise behaviour. This demonstrates that this estimator correctly estimates the noise bias and subtracts this out to yield an unbiased estimate of the power spectrum. More than $47\%$ of the frequency channels had to be discarded from the data owing to radio-frequency interference, however the estimated power spectrum does not show any artifacts due to missing channels. Finally, we show that it is possible to suppress the foreground contribution by tapering the sky response at large angular separations from the phase center. We combine the k modes within a rectangular region in the `EoR window' to obtain the spherically binned averaged dimensionless power spectra ${\Delta }^2(k)$ along with the statistical error $\sigma$ associated with the measured ${\Delta }^2(k)$. The lowest $k$-bin yields ${\Delta }^2(k)=(61.47{)}^2{\mathrm{K}}^2$ at $k=1.59{\text{Mpc}}^{-1}$, with $\sigma =(27.40{)}^2{\mathrm{K}}^2$. We obtain a $2\sigma$ upper limit of $(72.66{)}^2{\text{K}}^2$ on the mean squared HI 21-cm brightness temperature fluctuations at $k=1.59{\text{Mpc}}^{-1}$.

arXiv comment15 pages, 12 figures, Accepted for publication in MNRAS

References in corpus (48)

• Bright Source Subtraction Requirements For Redshifted 21 cm Measurements
• What Next-Generation 21 cm Power Spectrum Measurements Can Teach Us About the Epoch of Reionization
• 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
• Improved upper limits on the 21-cm signal power spectrum of neutral hydrogen at $\mathbf{z}\approx 9.1$ from LOFAR
• Upper limits on the 21-cm Epoch of Reionization power spectrum from one night with LOFAR
• 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
• Deep multi-redshift limits on Epoch of Reionisation 21cm Power Spectra from Four Seasons of Murchison Widefield Array Observations
• The Epoch of Reionization Window: II. Statistical Methods for Foreground Wedge Reduction
• Overcoming real-world obstacles in 21 cm power spectrum estimation: A method demonstration and results from early Murchison Widefield Array data
• All-Sky Interferometry with Spherical Harmonic Transit Telescopes
• The GMRT-EoR Experiment: A new upper limit on the neutral hydrogen power spectrum at z~8.6
• Foreground Contamination in Interferometric Measurements of the Redshifted 21 cm Power Spectrum
• Foreground Removal using FastICA: A Showcase of LOFAR-EoR
• Coaxing Cosmic 21cm Fluctuations from the Polarized Sky using m-mode Analysis
• A simplified, lossless re-analysis of PAPER-64
• Power Spectrum Sensitivity and the Design of Epoch of Reionization Observatories
• CHIPS: The Cosmological HI Power Spectrum Estimator
• Statistical 21-cm Signal Separation via Gaussian Process Regression Analysis
• Empirical Covariance Modeling for 21 cm Power Spectrum Estimation: A Method Demonstration and New Limits from Early Murchison Widefield Array 128-Tile Data
• The multi-frequency angular power spectrum of the epoch of reionization 21 cm signal
• The first power spectrum limit on the 21-cm signal of neutral hydrogen during the Cosmic Dawn at z=20-25 from LOFAR
• HI Fluctuations at Large Redshifts: I--Visibility correlation
• First Season MWA Phase II EoR Power Spectrum Results at Redshift 7
• 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?
• Tight Constraints on the Excess Radio Background at $z=9.1$ from LOFAR
• Visibility based angular power spectrum estimation in low frequency radio interferometric observations
• FLAGCAL:A flagging and calibration package for radio interferometric data
• Spherical Harmonic Analyses of Intensity Mapping Power Spectra
• Exploring the Origins of Deuterium Enrichments in Solar Nebular Organics
• GMRT observation towards detecting the Post-reionization 21-cm signal
• The visibility based Tapered Gridded Estimator (TGE) for the redshifted 21-cm power spectrum
• Detailed study of ELAIS N1 field with the uGMRT -- II. Source Properties and Spectral Variation Of Foreground Power Spectrum from 300-500 MHz Observations
• Polarization leakage in epoch of reionization windows: III. Wide-field effects of narrow-field arrays
• Tapering the sky response for angular power spectrum estimation from low-frequency radio-interferometric data
• Foreground modelling via Gaussian process regression: an application to HERA data
• Predictions for measuring the 21-cm multi-frequency angular power spectrum using SKA-Low
• Detecting Cosmic Reionization using Bi-Spectrum Phase
• A Tapered Gridded Estimator (TGE) for the Multi-Frequency Angular Power Spectrum (MAPS) and the Cosmological HI 21-cm Power Spectrum
• All sky angular power spectrum: I. Estimating brightness temperature fluctuations using TGSS 150 MHz survey
• Detailed study of the ELAIS N1 field with the uGMRT - I. Characterizing the 325 MHz foreground for redshifted 21 cm observations
• Detection of Cosmic Structures using the Bispectrum Phase. II. First Results from Application to Cosmic Reionization Using the Hydrogen Epoch of Reionization Array
• Characterizing EoR foregrounds: A study of the Lockman Hole Region at 325 MHz
• 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

Cited by in corpus (15)

• 21cmFirstCLASS I. Cosmological tool for $\Lambda$CDM and beyond
• Towards 21-cm Intensity Mapping at $z=2.28$ with uGMRT using the Tapered Gridded Estimator I: Foreground Avoidance
• CII and HI 21-cm line intensity mapping from the EoR: Impact of the light-cone effect on auto and cross-power spectra
• The multi-frequency angular power spectrum in parameter studies of the cosmic 21-cm signal
• Towards $21$-cm intensity mapping at $z=2.28$ with uGMRT using the tapered gridded estimator III: Foreground removal
• 21cmFirstCLASS II. Early linear fluctuations of the 21cm signal
• Towards $21$-cm intensity mapping at $z=2.28$ with uGMRT using the tapered gridded estimator -- IV. Wideband analysis
• Towards $21$-cm intensity mapping at $z=2.28$ with uGMRT using the tapered gridded estimator II: Cross-polarization 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
• The Tracking Tapered Gridded Estimator (TTGE) for the power spectrum from drift scan observations
• A Comparative Analysis To Deal With Missing Spectral Information Caused By RFI In Cosmological HI 21CM Observations
• Large HI optical depth and Redshifted 21-cm signal from cosmic dawn
• The Effect of Large Optical Depths on the Non-Gaussian 21-cm signal from Cosmic Dawn
• The Evolving Power Spectrum for the light cone Epoch of Reionization (EoR) 21-cm signal
• Bayes-SCF: A Bayesian filter to mitigate foreground leakage in the 21-cm power spectrum