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We implement an estimator for determining the separation between two incoherent point sources. This estimator relies on image inversion interferometry and when used with the appropriate data analytics, it yields an estimate of the…

Optics · Physics 2016-05-31 Tang Zong Sheng , Kadir Durak , Alexander Ling

Recent theoretical developments for observing the Epoch of Reionization (EOR) have concentrated on the power spectrum signature of redshifted 21 cm emission. These studies have demonstrated the great potential of statistical EOR…

Astrophysics · Physics 2009-11-10 Miguel F. Morales

Radio-interferometric arrays require very precise calibration to detect the Epoch of Reionization 21-cm signal. A remarkably complete and accurate sky model is therefore needed in the patches of the sky used to perform the calibration.…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-13 Khandakar Md Asif Elahi , Samir Choudhuri , Nirupam Roy , Md Rashid , Philip Bull , Dharam Vir Lal

We present the first limits on the Epoch of Reionization (EoR) 21-cm HI power spectra, in the redshift range $z=7.9-10.6$, using the Low-Frequency Array (LOFAR) High-Band Antenna (HBA). In total 13\,h of data were used from observations…

21cm emission from residual neutral hydrogen after the epoch of reionization can be used to trace the cosmological power spectrum of density fluctuations. Using a Fisher matrix formulation, we provide a detailed forecast of the constraints…

Astrophysics · Physics 2009-11-13 Eli Visbal , Abraham Loeb , Stuart Wyithe

The first measurements of the 21 cm brightness temperature power spectrum from the epoch of reionization will very likely be achieved in the near future by radio interferometric array experiments such as the Hydrogen Epoch of Reionization…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-22 Xiaosheng Zhao , Yi Mao , Benjamin D. Wandelt

We present new constraints on the 21cm Epoch of Reionization (EoR) power spectrum derived from 3 months of observing with a 32-antenna, dual-polarization deployment of the Donald C. Backer Precision Array for Probing the Epoch of…

We use the latest multi-redshift ($z=6.5-8.7$) upper limits on the 21-cm signal from the Murchison Widefield Array (MWA) to explore astrophysical models which are inconsistent with the data. These upper limits are achieved using 298 h of…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-25 Bradley Greig , Cathryn M. Trott , Nichole Barry , Simon J. Mutch , Bart Pindor , Rachel L. Webster , J. Stuart B. Wyithe

Radio-frequency interference (RFI) is a major systematic limitation in radio astronomy, particularly for science cases requiring high sensitivity, such as 21 cm cosmology. Traditionally, RFI is dealt with by identifying its signature in the…

A major obstacle to attain the fundamental precision limit of the phase estimation in an interferometry is the identification and implementation of the optimal measurement. Here we demonstrate that this can be accomplished by the use of…

Quantum Physics · Physics 2017-05-10 Wei Zhong , Yixiao Huang , Xiaoguang Wang , Shi-Liang Zhu

All observations by the aperture photometer (PHT-P) and the far-infrared (FIR) camera section (PHT-C) of ISOPHOT included reference measurements against stable internal fine calibration sources (FCS) to correct for temporal drifts in…

We present deep upper limits from the 2014 Murchison Widefield Array (MWA) Phase I observing season, with a particular emphasis on identifying the spectral fingerprints of extremely faint radio frequency interference (RFI) contamination in…

Radio interferometers aiming to measure the power spectrum of the redshifted 21 cm line during the Epoch of Reionisation (EoR) need to achieve an unprecedented dynamic range to separate the weak signal from overwhelming foreground…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-12 Pascal M. Keller , Bojan Nikolic , Nithyanandan Thyagarajan , Chris L. Carilli , Gianni Bernardi , Ntsikelelo Charles , Landman Bester , Oleg M. Smirnov , Nicholas S. Kern , Joshua S. Dillon , Bryna J. Hazelton , Miguel F. Morales , Daniel C. Jacobs , Aaron R. Parsons , Zara Abdurashidova , Tyrone Adams , James E. Aguirre , Paul Alexander , Zaki S. Ali , Rushelle Baartman , Yanga Balfour , Adam P. Beardsley , Tashalee S. Billings , Judd D. Bowman , Richard F. Bradley , Philip Bull , Jacob Burba , Steven Carey , Carina Cheng , David R. DeBoer , Eloy de Lera Acedo , Matt Dexter , Nico Eksteen , John Ely , Aaron Ewall-Wice , Nicolas Fagnoni , Randall Fritz , Steven R. Furlanetto , Kingsley Gale-Sides , Brian Glendenning , Deepthi Gorthi , Bradley Greig , Jasper Grobbelaar , Ziyaad Halday , Jacqueline N. Hewitt , Jack Hickish , 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 , Hans Nuwegeld , Robert Pascua , Nipanjana Patra , Samantha Pieterse , Jonathan C. Pober , Nima Razavi-Ghods , James Robnett , Kathryn Rosie , Mario G. Santos , Peter Sims , Craig Smith , Hilton Swarts , Pieter Van Wyngaarden , Peter K. G. Williams , Haoxuan Zheng

Radio-frequency interference (RFI) presents a significant obstacle to current radio interferometry experiments aimed at the Epoch of Reionization. RFI contamination is often several orders of magnitude brighter than the astrophysical…

Instrumentation and Methods for Astrophysics · Physics 2025-03-05 Jade M. Ducharme , Jonathan C. Pober

We present limits on the 21cm power spectrum from the Epoch of Reionization (EoR) using data from the 64 antenna configuration of the Donald C. Backer Precision Array for Probing the Epoch of Reionization (PAPER) analyzed through a power…

With a statistical detection of the 21 cm signal fluctuations from the Epoch of Reionization (EoR) expected in the next few years, there is an interest in developing robust and precise techniques to constrain the underlying astrophysical…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 Evan Eames , Aristide Doussot , Benoît Semelin

Observation of multifrequency angular power spectrum of the redshifted 21-cm brightness temperature fluctuation from the neutral hydrogen holds the key to understand the structure formation and its evolution during the reionization and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-28 Saikat Gayen , Jais Kumar , Prasun Dutta , Khandakar Md Asif Elahi , Samir Choudhuri , Nirupam Roy

The redshifted 21 cm line of neutral hydrogen is a promising probe of the Epoch of Reionization (EoR). However, its detection requires a thorough understanding and control of the systematic errors. We study two systematic biases observed in…

To achieve the sensitivity required to detect signals from neutral hydrogen from the Cosmic Dawn and Epoch of Reionisation it is critical to have a well-calibrated instrument which has a stable calibration over the course of the…

Instrumentation and Methods for Astrophysics · Physics 2026-03-04 Christian J. Kirkham , Dominic J. Anstey , Eloy de Lera Acedo
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