15 citations · 58 across the 20 of their papers we have counts for
23 papers
Calibration requirements for Epoch of Reionization 21-cm signal observations - V. Bias and variance in the cylindrical power spectrum from uGMRT Band 3 observations of the ELAIS-N1 field
Saikat Gayen, Suvam Tripathy, Saqueb Tanveer +13
Detection of the redshifted 21-cm signal from neutral hydrogen requires precise control of systematic effects arising from instrumental calibration. In this work, we investigate th…
Constraining the neutral hydrogen (HI) distribution
Minal Chhabra, Raghunath Ghara, Somnath Bharadwaj
We constrain the HI distribution by jointly modeling two independent, existing observations of the 21-cm signal, the HI density parameter measured using…
Accurate parameter inference for the Light-cone Epoch of Reionization 21-cm signal
Suman Pramanick, Anoop Krishna, Rajesh Mondal +1
The light-cone (LC) effect introduces line-of-sight (LoS) statistical inhomogeneity into the 21-cm signal. Consequently, the traditional power spectrum (PS) fails to capture the fu…
Methodological Frontiers in 21-cm Intensity Mapping: the Treatment of Systematics and Foreground Contamination
Marta Spinelli, Matilde Barberi-Squarotti, José Luis Bernal +29
The distribution of neutral hydrogen (HI) in the post-reionization universe traces the cosmic large-scale structure and therefore serves as a powerful cosmological probe. An effici…
Observations of the Cosmic Dawn and Epoch of Reionization with the SKAO: Observational Lessons Learned from Precursors and Pathfinder Instruments
Eloy de Lera Acedo, James Aguirre, Dominic Anstey +34
This chapter summarizes the observational lessons learned after two decades of observations of the Cosmic Dawn (CD) and Epoch of Reionization (EoR) with SKAO pathfinders and precur…
Observational Frontiers in the post-EoR 21-cm Intensity Mapping: Lessons from the SKA Pathfinders
Khandakar Md Asif Elahi, Somnath Bharadwaj, Philip Bull +21
The 21-cm line from neutral hydrogen has long been recognised as a promising tracer of the large-scale structure of the Universe. The line is weak however, making individual galaxy…
The Tracking Tapered Gridded Estimator for the 21-cm power spectrum from the Murchison Widefield Array (MWA) drift scan observations -- III. Improved upper limits at from multiple pointings
Shouvik Sarkar, Khandakar Md Asif Elahi, Samir Choudhuri +5
We analyze zenith-pointing Murchison Widefield Array (MWA) drift scan observations covering with 1…
The Epoch of Reionization 21 cm Bispectrum at from MWA data II: Smooth Component Filtering
Sukhdeep Singh Gill, Khandakar Md Asif Elahi, Somnath Bharadwaj +2
The 21 cm bispectrum (BS) offers a powerful probe of the Epoch of Reionization (EoR), but its observational access is severely hindered by dominant astrophysical foregrounds. Consi…
ELAIS-N1 deep field uGMRT Band-2: constraints on diffuse Galactic synchrotron emission power spectrum
Rashmi Sagar, Abhirup Datta, Arnab Chakraborty +13
We present high sensitivity, low radio frequency continuum observations of the ELAIS-N1 field with 32 hours of observations of the uGMRT Band-2 ( MHz) covering $5.86\,\tex…
Probing the HI distribution at small scales using 21-cm Intensity Mapping at large scales
Minal Chhabra, Somnath Bharadwaj
Neutral hydrogen (HI) 21-cm Intensity Mapping (IM) holds the potential to map the large-scale structures in the Universe over a wide redshift range , measure cosm…
The EoR 21-cm Bispectrum at from MWA data I: Foregrounds and preliminary upper limits
Sukhdeep Singh Gill, Somnath Bharadwaj, Khandakar Md Asif Elahi +2
We attempt to measure the Epoch of Reionization (EoR) 21-cm bispectrum (BS) using Murchison Widefield Array (MWA) data. We find that $B(k_{1\perp}, k…
A measurement of Galactic synchrotron emission using MWA drift scan observations
Suman Chatterjee, Shouvik Sarkar, Samir Choudhuri +4
Studying the diffuse Galactic synchrotron emission (hereafter, DGSE) at arc-minute angular scale is important to remove the foregrounds for the cosmological 21-cm observations. Sta…
A Visibility-based 21 cm Bispectrum Estimator for Radio-interferometric Data
Sukhdeep Singh Gill, Somnath Bharadwaj
We present a fast and scalable estimator for the binned multi-frequency angular bispectrum (MABS) and the 3D bispectrum (BS) of the redshifted 21 cm signal from radio interferometr…
The Evolving Power Spectrum for the light cone Epoch of Reionization (EoR) 21-cm signal
Suman Pramanick, Somnath Bharadwaj, Khandakar Md Asif Elahi +1
The rapid evolution of the cosmological neutral hydrogen (HI) distribution during the EoR is imprinted along the line of sight (LoS) in the redshifted 21-cm signal due to the light…
A visibility-based angular bispectrum estimator for radio-interferometric data
Sukhdeep Singh Gill, Somnath Bharadwaj, Sk. Saiyad Ali +1
Considering radio-interferometric observations, we present a fast and efficient estimator to compute the binned angular bispectrum (ABS) from gridded visibility data. The estimator…
The Tracking Tapered Gridded Estimator for the 21-cm power spectrum from MWA drift scan observations II: The Missing Frequency Channels
Khandakar Md Asif Elahi, Somnath Bharadwaj, Suman Chatterjee +4
Missing frequency channels pose a problem for estimating the redshifted 21-cm power spectrum (PS) from radio-interferometric visibility data. This is parti…
The Tracking Tapered Gridded Estimator for the 21-cm power spectrum from MWA drift scan observations I: Validation and preliminary results
Suman Chatterjee, Khandakar Md Asif Elahi, Somnath Bharadwaj +4
Drift scan observations provide the broad sky coverage and instrumental stability needed to measure the Epoch of Reionization (EoR) 21-cm signal. In such observations, the telescop…
Brisk estimator for the angular multipoles of the redshift space bispectrum
Sukhdeep Singh Gill, Somnath Bharadwaj
The anisotropy of the redshift space bispectrum depends upon the orientation of the triangles formed by three modes with respect to the line of sight. For a triangle o…
Towards -cm intensity mapping at with uGMRT using the tapered gridded estimator -- IV. Wideband analysis
Khandakar Md Asif Elahi, Somnath Bharadwaj, Srijita Pal +8
We present a Wideband Tapered Gridded Estimator (TGE), which incorporates baseline migration and variation of the primary beam pattern for neutral hydrogen (${\rm H\hspace{0.5mm}}{…
The size and shape dependence of the SDSS galaxy bispectrum
Anindita Nandi, Sukhdeep Singh Gill, Debanjan Sarkar +3
We have measured the spherically averaged bispectrum of the SDSS main galaxy sample, considering a volume-limited data cube with mean galaxy number density $…
The monopole and quadrupole moments of the Epoch of Reionization (EoR) 21-cm bispectrum
Sukhdeep Singh Gill, Suman Pramanick, Somnath Bharadwaj +2
We study the monopole () and quadrupole () moments of the 21-cm bispectrum (BS) from EoR simulations and present results for squeezed and stretched triang…
Fisher matrix predictions for detecting the cosmological 21 cm signal with the Ooty Wide Field Array (OWFA)
Somnath Bharadwaj, Anjan Kumar Sarkar, Sk. Saiyad Ali
We have used the Fisher matrix formalism to quantify the prospects of detecting the z = 3.35 redshifted 21-cm HI power spectrum with the upcoming radio-imterferometric array OWFA.…
A 2D analysis of percolation and filamentarity in the SDSS DR1
Biswajit Pandey, Somnath Bharadwaj
We have used the Largest Cluster Statistics and the Average Filamentarity to quantify respectively the connectivity and the shapes of the patterns seen in the galaxy distribution i…