4.7 Article

Towards 21-cm intensity mapping at z=2.28 with uGMRT using the tapered gridded estimator I: Foreground avoidance

Related references

Note: Only part of the references are listed.
Article Astronomy & Astrophysics

HI constraints from the cross-correlation of eBOSS galaxies and Green Bank Telescope intensity maps

Laura Wolz et al.

Summary: This study presents a joint analysis of Neutral Hydrogen (HI) Intensity Mapping observations with three galaxy samples covering the redshift range 0.6 < z < 1.0. The HI data is processed by separating and removing foregrounds using FAsTI ICA. The cleaned HI data is then cross-correlated with galaxy samples to study the amplitude and scale dependence of the power spectrum. The results provide precise constraints on neutral hydrogen density fluctuations in an underexplored redshift range.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Article Astronomy & Astrophysics

Calibration requirements for Epoch of Reionization 21-cm signal observations - II. Analytical estimation of the bias and variance with time-correlated residual gains

Jais Kumar et al.

Summary: This paper studies the impact of time-correlated residual gain errors on signal observations in the presence of strong foreground. It proposes a method to analytically estimate the bias and variance in the power spectrum, and validates its effectiveness using simulated observations. The results show that as the standard deviation of residual gain errors increases, the bias in the estimation becomes dominant. Optimal choice of the time for gain solution estimation minimizes the risk, and interferometers with higher baseline densities are preferred for these studies.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2022)

Article Astronomy & Astrophysics

Demonstrating the Tapered Gridded Estimator (TGE) for the cosmological HI 21-cm power spectrum using 150-MHz GMRT observations

Srijita Pal et al.

Summary: The study utilizes the Tapered Gridded Estimator to estimate the cosmological 21-cm power spectrum from 150-MHz GMRT observations, demonstrating its ability to accurately estimate noise bias, suppress foreground contributions, and avoid artifacts from missing data channels.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Article Astronomy & Astrophysics

The auto- and cross-angular power spectrum of the Cas A supernova remnant in radio and X-ray

Preetha Saha et al.

Summary: The shell type supernova remnant Cas A shows structures at different angular scales. The study reveals broken power-law behavior in radio and X-ray emissions, with strong correlations observed between X-ray B and both radio and X-ray A, supporting the hypothesis of thermal bremsstrahlung and non-thermal synchrotron emission. These findings provide insights into the nature of turbulence and emission mechanisms in Cas A.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Article Astronomy & Astrophysics

Statistical recovery of the BAO scale from multipoles of the beam-convolved 21cm correlation function

Fraser Kennedy et al.

Summary: By analyzing low angular resolution 21cm intensity mapping survey data, it was found that the recovery of the transverse BAO scale is hindered by instrumental beam effects, while the radial scale is more robust. The multipole formalism naturally incorporates transverse information when available, eliminating the need for radial-only analysis.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2021)

Article Astronomy & Astrophysics

First Multi-redshift Limits on Post-Epoch of Reionization 21 cm Signal from z=1.96-3.58 Using uGMRT

Arnab Chakraborty et al.

Summary: Measurement of fluctuations in diffuse Hi 21 cm background radiation from the post-reionization epoch (z <= 6) provides stringent upper limits on the spherically averaged 21 cm power spectra and constrains the product of the neutral Hi mass density and Hi bias to the underlying dark matter density field at different redshifts. These results are the first limits on the Hi 21 cm power spectra in the redshift range z = 1.96-3.58 and are essential for constraining models of galaxy formation and evolution.

ASTROPHYSICAL JOURNAL LETTERS (2021)

Article Astronomy & Astrophysics

Planck 2018 results: VI. Cosmological parameters

N. Aghanim et al.

ASTRONOMY & ASTROPHYSICS (2020)

Article Astronomy & Astrophysics

All-sky angular power spectrum - I. Estimating brightness temperature fluctuations using the 150-MHz TGSS survey

Samir Choudhuri et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2020)

Article Astronomy & Astrophysics

Characterizing EoR foregrounds: a study of the Lockman Hole region at 325 MHz

Aishrila Mazumder et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2020)

Article Astronomy & Astrophysics

Calibration requirements for epoch of reionization 21-cm signal observations - I. Effect of time-correlated gains

Jais Kumar et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2020)

Article Astronomy & Astrophysics

Detailed study of the ELAIS N1 field with the uGMRT - I. Characterizing the 325 MHz foreground for redshifted 21 cm observations

Arnab Chakraborty et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2019)

Article Astronomy & Astrophysics

A study of Kepler supernova remnant: angular power spectrum estimation from radio frequency data

Preetha Saha et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2019)

Article Astronomy & Astrophysics

Detailed study of ELAIS N1 field with the uGMRT - II. Source properties and spectral variation of foreground power spectrum from 300-500 MHz observations

Arnab Chakraborty et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2019)

Article Astronomy & Astrophysics

A Tapered Gridded Estimator (TGE) for the multifrequency angular power spectrum (MAPS) and the cosmological H I 21-cm power spectrum

Somnath Bharadwaj et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2019)

Article Astronomy & Astrophysics

A method to determine the evolution history of the mean neutral Hydrogen fraction

Rajesh Mondal et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2019)

Article Astronomy & Astrophysics

Wide-field LOFAR-LBA power-spectra analyses: impact of calibration, polarization leakage, and ionosphere

B. K. Gehlot et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2018)

Article Astronomy & Astrophysics

Low-amplitude clustering in low-redshift 21-cm intensity maps cross-correlated with 2dF galaxy densities

C. J. Anderson et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2018)

Article Astronomy & Astrophysics

The Effect of Baseline Layouts on the Epoch of Reionization Foreground Wedge: A Semianalytical Approach

Steven G. Murray et al.

ASTROPHYSICAL JOURNAL (2018)

Article Astronomy & Astrophysics

The Ooty Wide Field Array

C. R. Subrahmanya et al.

JOURNAL OF ASTROPHYSICS AND ASTRONOMY (2017)

Article Astronomy & Astrophysics

The angular power spectrum measurement of the Galactic synchrotron emission in two fields of the TGSS survey

Samir Choudhuri et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2017)

Article Multidisciplinary Sciences

The upgraded GMRT: opening new windows on the radio Universe

Y. Gupta et al.

CURRENT SCIENCE (2017)

Article Astronomy & Astrophysics

Tapering the sky response for angular power spectrum estimation from low-frequency radio-interferometric data

Samir Choudhuri et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2016)

Article Astronomy & Astrophysics

Modelling the post-reionization neutral hydrogen (H I ) bias

Debanjan Sarkar et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2016)

Article Astronomy & Astrophysics

The visibility-based tapered gridded estimator (TGE) for the redshifted 21-cm power spectrum

Samir Choudhuri et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2016)

Article Astronomy & Astrophysics

CONFIRMATION OF WIDE-FIELD SIGNATURES IN REDSHIFTED 21 cm POWER SPECTRA

Nithyanandan Thyagarajan et al.

ASTROPHYSICAL JOURNAL LETTERS (2015)

Article Astronomy & Astrophysics

FOREGROUNDS IN WIDE-FIELD REDSHIFTED 21 cm POWER SPECTRA

Nithyanandan Thyagarajan et al.

ASTROPHYSICAL JOURNAL (2015)

Article Astronomy & Astrophysics

Prospects for Detecting the 326.5 MHz Redshifted 21-cm HI Signal with the Ooty Radio Telescope (ORT)

Sk. Saiyad Ali et al.

JOURNAL OF ASTROPHYSICS AND ASTRONOMY (2014)

Article Astronomy & Astrophysics

Visibility-based angular power spectrum estimation in low-frequency radio interferometric observations

Samir Choudhuri et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2014)

Article Astronomy & Astrophysics

MEASUREMENT OF 21 cm BRIGHTNESS FLUCTUATIONS AT z ∼ 0.8 IN CROSS-CORRELATION

K. W. Masui et al.

ASTROPHYSICAL JOURNAL LETTERS (2013)

Article Astronomy & Astrophysics

Determination of z ∼ 0.8 neutral hydrogen fluctuations using the 21 cm intensity mapping autocorrelation

E. R. Switzer et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2013)

Article Astronomy & Astrophysics

A morphological algorithm for improving radio-frequency interference detection

A. R. Offringa et al.

ASTRONOMY & ASTROPHYSICS (2012)

Article Astronomy & Astrophysics

IMAGING THE EPOCH OF REIONIZATION: LIMITATIONS FROM FOREGROUND CONFUSION AND IMAGING ALGORITHMS

Harish Vedantham et al.

ASTROPHYSICAL JOURNAL (2012)

Article Astronomy & Astrophysics

FOUR FUNDAMENTAL FOREGROUND POWER SPECTRUM SHAPES FOR 21 cm COSMOLOGY OBSERVATIONS

Miguel F. Morales et al.

ASTROPHYSICAL JOURNAL (2012)

Article Astronomy & Astrophysics

Characterizing foreground for redshifted 21 cm radiation: 150 MHz Giant Metrewave Radio Telescope observations

Abhik Ghosh et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2012)

Article Physics, Multidisciplinary

Primordial Non-Gaussianity in the Forest: 3D Bispectrum of Lyman-α Flux Spectra along Multiple Lines of Sight

Dhiraj Kumar Hazra et al.

PHYSICAL REVIEW LETTERS (2012)

Article Astronomy & Astrophysics

GMRT observation towards detecting the post-reionization 21-cm signal

Abhik Ghosh et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2011)

Article Astronomy & Astrophysics

Improved foreground removal in GMRT 610 MHz observations towards redshifted 21-cm tomography

Abhik Ghosh et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2011)

Article Astronomy & Astrophysics

Post-correlation radio frequency interference classification methods

A. R. Offringa et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2010)

Article Multidisciplinary Sciences

An intensity map of hydrogen 21-cm emission at redshift z ≈ 0.8

Tzu-Ching Chang et al.

NATURE (2010)

Article Astronomy & Astrophysics

CALIBRATION OF LOW-FREQUENCY, WIDE-FIELD RADIO INTERFEROMETERS USING DELAY/DELAY-RATE FILTERING

Aaron R. Parsons et al.

ASTRONOMICAL JOURNAL (2009)

Article Astronomy & Astrophysics

FOREGROUND CONTAMINATION IN INTERFEROMETRIC MEASUREMENTS OF THE REDSHIFTED 21 cm POWER SPECTRUM

Judd D. Bowman et al.

ASTROPHYSICAL JOURNAL (2009)

Article Astronomy & Astrophysics

Cosmological constraints from 21cm surveys after reionization

Eli Visbal et al.

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS (2009)

Article Astronomy & Astrophysics

Estimation of cosmological parameters from neutral hydrogen observations of the post-reionization epoch

Somnath Bharadwaj et al.

PHYSICAL REVIEW D (2009)

Article Astronomy & Astrophysics

First detection of cosmic structure in the 21-cm intensity field

Ue-Li Pen et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2009)

Article Physics, Multidisciplinary

Baryon acoustic oscillation intensity mapping of dark energy

Tzu-Ching Chang et al.

PHYSICAL REVIEW LETTERS (2008)

Article Astronomy & Astrophysics

Baryonic acoustic oscillations in 21-cm emission: a probe of dark energy out to high redshifts

J. Stuart B. Wyithe et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2008)

Article Astronomy & Astrophysics

The multifrequency angular power spectrum of the epoch of reionization 21-cm signal

Kanan K. Datta et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2007)

Article Astronomy & Astrophysics

On using visibility correlations to probe the HI distribution from the dark ages to the present epoch - I. Formalism and the expected signal

S Bharadwaj et al.

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY (2005)

Article Astronomy & Astrophysics

Toward epoch of reionization measurements with wide-field radio observations

MF Morales et al.

ASTROPHYSICAL JOURNAL (2004)

Article Astronomy & Astrophysics

HI fluctuations at large redshifts: II - the signal expected for the GMRT

S Bharadwaj et al.

JOURNAL OF ASTROPHYSICS AND ASTRONOMY (2003)

Article Astronomy & Astrophysics

HI fluctuations at large redshifts: I - Visibility correlation

S Bharadwaj et al.

JOURNAL OF ASTROPHYSICS AND ASTRONOMY (2001)

Article Astronomy & Astrophysics

Using HI to probe large scale structures at z∼3

S Bharadwaj et al.

JOURNAL OF ASTROPHYSICS AND ASTRONOMY (2001)