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Reconstruction of the sky brightness measured by radio interferometers is typically achieved through gridding techniques, or histograms in spatial Fourier space. For Epoch of Reionisation (EoR) 21 cm power spectrum measurements, extreme…

Instrumentation and Methods for Astrophysics · Physics 2022-04-22 Nichole Barry , Aman Chokshi

We present a method for extracting the expected cosmological 21-cm signal from the epoch of reionization, taking into account contaminating radiations and random instrumental noise. The method is based on the maximum a-posteriori…

Astrophysics · Physics 2008-12-21 Liron Gleser , Adi Nusser , Andrew J. Benson

Foreground removal is a major challenge for detecting the redshifted 21-cm neutral hydrogen (HI) signal from the Epoch of Reionization (EoR). We have used 150 MHz GMRT observations to characterize the statistical properties of the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-24 Abhik Ghosh , Jayanti Prasad , Somnath Bharadwaj , Sk. Saiyad Ali , Jayaram N. Chengalur

Accurate modelling of the primary beam is an important but difficult task in radio astronomy. For high dynamic range problems such as 21cm intensity mapping, small modelling errors in the sidelobes and spectral structure of the beams can…

Instrumentation and Methods for Astrophysics · Physics 2024-07-25 Michael J. Wilensky , Jacob Burba , Philip Bull , Hugh Garsden , Katrine A. Glasscock , Nicolas Fagnoni , Eloy de Lera Acedo , David R. DeBoer , Nima Razavi-Ghods

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

A critical challenge in measuring the power spectrum of 21cm emission from cosmic reionization is compensating for the frequency dependence of an interferometer's sampling pattern, which can cause smooth-spectrum foregrounds to appear…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 Aaron R. Parsons , Jonathan C. Pober , James E. Aguirre , Christopher L. Carilli , Daniel C. Jacobs , David F. Moore

Numerous studies have established the theoretical potential of the 21cm bispectrum to boost our understanding of the Epoch of Reionization (EoR), and therefore early generation of stars and galaxies. In this paper we look at the impact of…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-09 Catherine A Watkinson , Cathryn M Trott , Ian Hothi

The birth of the first luminous sources and the ensuing epoch of reionization are best studied via the redshifted 21-cm emission line, the signature of the first two imprinting the last. In this work we present a fully-Bayesian method,…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-27 G. Bernardi , J. T. L. Zwart , D. Price , L. J. Greenhill , A. Mesinger , J. Dowell , T. Eftekhari , S. W. Ellingson , J. Kocz , F. Schinzel

We propose the HI 21-cm power spectrum from the post-reionization epoch as a probe of a cosmological model with decaying dark matter particles. The unstable particles are assumed to undergo a 2-body decay into a massless and massive…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-12 Mohit Yadav , Tapomoy Guha Sarkar

We study the prospects for extracting detailed statistical properties of the neutral Hydrogen distribution during the era of reionization using the brightness temperature fluctuations from redshifted 21 cm line emission. Detection of this…

Astrophysics · Physics 2009-11-10 M. G. Santos , A. Cooray , L. Knox

The redshifted 21-cm signal from neutral hydrogen (HI) in the intergalactic medium (IGM) is a powerful probe of the Epoch of Reionization (EoR). Owing to the complex growth and morphology of ionized regions, the 21-cm brightness-temperature…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-19 Vishrut Pandya , Leon Noble , Suman Majumdar , Debanjan Sarkar , Mohd Kamran , Abhirup Datta

Measurement of the 21cm hyperfine transition of neutral hydrogen provides a unique probe of the epoch of reionization and the Dark Ages. Three major mechanisms are believed to dominate the radiation process: emission from neutral hydrogen…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Qian Zheng

The study of the cosmic Dark Ages, Cosmic Dawn, and Epoch of Reionization (EoR) using the all-sky averaged redshifted HI 21cm signal, are some of the key science goals of most of the ongoing or upcoming experiments, for example, EDGES,…

Cosmology and Nongalactic Astrophysics · Physics 2019-12-24 Madhurima Choudhury , Abhirup Datta , Arnab Chakraborty

The measurements of the 21-cm brightness temperature fluctuations from the neutral hydrogen at the Epoch of Reionization (EoR) should inaugurate the next generation of cosmological observables. In this respect, many works have concentrated…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-10 Sebastien Clesse , Laura Lopez-Honorez , Christophe Ringeval , Hiroyuki Tashiro , Michel H. G. Tytgat

The 21 cm hyperfine transition of neutral hydrogen offers a promising probe of the large scale structure of the universe before and during the Epoch of Reionization, when the first ionizing sources formed. Bright radio emission from…

Instrumentation and Methods for Astrophysics · Physics 2020-04-22 Adam E. Lanman , Jonathan C. Pober , Nicholas S. Kern , Eloy de Lera Acedo , David R. DeBoer , Nicolas Fagnoni

Cross-correlations between 21cm observations and galaxy surveys provide a powerful probe of reionization by reducing foreground sensitivity while linking ionization morphology to galaxies. We quantify the constraining power of 21cm-Galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-27 Yannic Pietschke , Anne Hutter , Caroline Heneka

For there to be a successful measurement of the 21 cm Epoch of Reionization (EoR) power spectrum, it is crucial that strong foreground contaminants be robustly suppressed. These foregrounds come from a variety of sources (such as Galactic…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-25 Adrian Liu , Aaron R. Parsons , Cathryn M. Trott

The epoch of reionization (EoR) 21-cm signal is expected to be highly non-Gaussian in nature and this non-Gaussianity is also expected to evolve with the progressing state of reionization. Therefore the signal will be correlated between…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-14 Suman Majumdar , Jonathan R. Pritchard , Rajesh Mondal , Catherine A. Watkinson , Somnath Bharadwaj , Garrelt Mellema