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The precise characterization and mitigation of systematic effects is one of the biggest roadblocks impeding the detection of the fluctuations of cosmological 21cm signals. Missing data in radio cosmological experiments, often due to radio…

Detecting cosmological signals from the Epoch of Reionization (EoR) requires high-precision calibration to isolate the cosmological signals from foreground emission. In radio interferometery, perturbed primary beams of antenna elements can…

Precise measurements of the 21 cm power spectrum are crucial for understanding the physical processes of hydrogen reionization. Currently, this probe is being pursued by low-frequency radio interferometer arrays. As these experiments come…

We investigate the use of closure phase as a method to detect the HI 21cm signal from the neutral IGM during cosmic reionzation. Closure quantities have the unique advantage of being independent of antenna-based calibration terms. We employ…

Instrumentation and Methods for Astrophysics · Physics 2016-07-04 C. L. Carilli , P. Sims

Measurement of the power spectrum of high redshift 21 cm emission from neutral hydrogen probes the formation of the first luminous objects and the ionization of intergalactic medium by the first stars. However, the 21 cm signal at these…

Instrumentation and Methods for Astrophysics · Physics 2025-08-13 Katherine Elder , Daniel C. Jacobs , Maria Kovaleva

The Epoch of Reionization (EoR) is an uncharted era in our Universe's history during which the birth of the first stars and galaxies led to the ionization of neutral hydrogen in the intergalactic medium. There are many experiments…

The redshifted 21-cm signal is a unique probe of the early universe, particularly the Epoch of Reionization (EoR). While the 21-cm power spectrum has been the primary statistic for parameter inference, it fails to capture the non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-03 Anoop Krishna , Deepthi Moorkanat , Hiten , Rajesh Mondal

Precision antenna calibration is required for mitigating the impact of foreground contamination in 21 cm cosmological radio surveys. One widely studied source of error is the effect of missing point sources in the calibration sky model;…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-19 Ntsikelelo Charles , Nicholas Kern , Gianni Bernardi , Landman Bester , Oleg Smirnov , Nicolas Fagnoni , Eloy de Lera Acedo

The redshifted 21cm signal of neutral hydrogen from the epoch of reionization (EoR) is extremely weak and its first detection is therefore expected to be statistical with first-generation low-frequency radio interferometers. In this letter…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Qian Zheng , Xiang-ping Wu , Jun-hua Gu , Jingying Wang , Haiguang Xu

Combining the visibilities measured by an interferometer to form a cosmological power spectrum is a complicated process. In a delay-based analysis, the mapping between instrumental and cosmological space is not a one-to-one relation.…

The Epoch of Reionization (EoR) features a rich interplay between the first luminous sources and the low-density gas of the intergalactic medium (IGM), where photons from these sources ionize the IGM. There are currently few observational…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-07 Paul La Plante , Michelle Ntampaka

Radio Frequency Interference (RFI) is one of the systematic challenges preventing 21cm interferometric instruments from detecting the Epoch of Reionization. To mitigate the effects of RFI on data analysis pipelines, numerous inpaint…

(Abridged) Noise considerations for experiments that aim to statistically estimate the 21 cm signal from high redshift neutral hydrogen during the Epoch of Reionisation (EoR) using interferometric data are typically computed assuming a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Cathryn M. Trott

The large-scale structure of the Universe should soon be measured at high redshift during the Epoch of Reionization (EoR) through line-intensity mapping. A number of ongoing and planned surveys are using the 21 cm line to trace neutral…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-01 Angus Beane , Francisco Villaescusa-Navarro , Adam Lidz

The Epoch of Reionization (EoR), when the first luminous sources ionised the intergalactic medium, represents a new frontier in cosmology. The Square Kilometre Array Observatory (SKAO) will offer unprecedented insights into this era through…

Motivated by the desire for wide-field images with well-defined statistical properties for 21cm cosmology, we implement an optimal mapping pipeline that computes a maximum likelihood estimator for the sky using the interferometric…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-28 Zhilei Xu , Jacqueline N. Hewitt , Kai-Feng Chen , Honggeun Kim , Joshua S. Dillon , Nicholas S. Kern , Miguel F. Morales , Bryna J. Hazelton , Ruby Byrne , Nicolas Fagnoni , Eloy de Lera Acedo , Zara Abdurashidova , Tyrone Adams , James E. Aguirre , Paul Alexander , Zaki S. Ali , Rushelle Baartman , Yanga Balfour , Adam P. Beardsley , Gianni Bernardi , Tashalee S. Billings , Judd D. Bowman , Richard F. Bradley , Philip Bull , Jacob Burba , Steven Carey , Chris L. Carilli , Carina Cheng , David R. DeBoer , Matt Dexter , Nico Eksteen , John Ely , Aaron Ewall-Wice , Randall Fritz , Steven R. Furlanetto , Kingsley Gale-Sides , Brian Glendenning , Deepthi Gorthi , Bradley Greig , Jasper Grobbelaar , Ziyaad Halday , Jack Hickish , Daniel C. Jacobs , Austin Julius , MacCalvin Kariseb , Joshua Kerrigan , Piyanat Kittiwisit , Saul A. Kohn , Matthew Kolopanis , Adam Lanman , Paul La Plante , Adrian Liu , Anita Loots , Yin-zhe Ma , David Harold Edward MacMahon , Lourence Malan , Cresshim Malgas , Keith Malgas , Bradley Marero , Zachary E. Martinot , Andrei Mesinger , Mathakane Molewa , Tshegofalang Mosiane , Steven G. Murray , Abraham R. Neben , Bojan Nikolic , Hans Nuwegeld , Aaron R. Parsons , Nipanjana Patra , Samantha Pieterse , Jonathan C. Pober , Nima Razavi-Ghods , James Robnett , Kathryn Rosie , Peter Sims , Craig Smith , Hilton Swarts , Nithyanandan Thyagarajan , Pieter Van Van Wyngaarden , Peter K. G. Williams , Haoxuan Zheng

The detection of redshifted hyperfine line of neutral hydrogen (HI) is the most promising probe of the Epoch of Reionization (EoR). We report an analysis of 55 hours of Murchison Widefield Array (MWA) Phase II drift scan EoR data. The data…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-21 Akash Kumar Patwa , Shiv Sethi , K. S. Dwarakanath

The observations of the redshifted 21-cm signal from neutral hydrogen are a promising probe for understanding the Cosmic Dawn and the Epoch of Reionisation (EoR). One of the primary obstacles to the statistical detection of the Cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-22 Eeshan Beohar , Abhirup Datta , Anshuman Tripathi , Samit Kumar Pal , Rashmi Sagar

One of the aims of the Low Frequency Array (LOFAR) Epoch of Reionization (EoR) project is to measure the power spectrum of variations in the intensity of redshifted 21-cm radiation from the EoR. The sensitivity with which this power…