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We investigate the implications of interference detection for experiments that are pursuing a detection of the redshifted 21-cm signals from the Epoch of Reionization. Interference detection causes samples to be sporadically flagged and…

Instrumentation and Methods for Astrophysics · Physics 2019-03-13 A. R. Offringa , F. Mertens , L. V. E. Koopmans

The 21 cm signal arising from fluctuations in the neutral hydrogen field, and its cross-correlation with other tracers of cosmic density, are promising probes of the high-redshift Universe. In this study, we assess the potential of the 21…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Barun Maity

We use the Fisher matrix formalism and semi-numerical simulations to derive quantitative predictions of the constraints that power spectrum measurements on next-generation interferometers, such as the Hydrogen Epoch of Reionization Array…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-26 Aaron Ewall-Wice , Jacqueline Hewitt , Andrei Mesinger , Joshua S. Dillon , Adrian Liu , Jonathan Pober

The cross-correlation between the 21 cm emission from the high-redshift intergalactic medium and the near-infrared (NIR) background light from the high-redshift galaxies promises to be a powerful probe of cosmic reionization. In this paper,…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Xiao-Chun Mao

The 21cm line brightness temperature brings rich information about Epoch of Reionizaton (EoR) and high-$z$ universe (Cosmic Dawn and Dark Age). While the power spectrum is a useful tool to investigate the EoR signal statistically,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Shintaro Yoshiura , Hayato Shimabukuro , Keitaro Takahashi , Rieko Momose , Hiroyuki Nakanishi , Hiroshi Imai

One of the most promising probes to constrain the reionization history of the universe is the power spectrum of neutral hydrogen 21 cm emission fluctuations. The corresponding analyses require computationally efficient modelling of…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-21 Barun Maity , Tirthankar Roy Choudhury

Upcoming experiments such as Hydrogen Epoch of Reionization Array (HERA) and Square Kilometre Array (SKA) are intended to measure the 21cm signal over a wide range of redshifts, representing an incredible opportunity in advancing our…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-06 Héctor J. Hortúa , Riccardo Volpi , Luigi Malagò

We discuss the prospects of using the redshifted 21~cm emission from neutral hydrogen in the post-reionization epoch to study our universe. The main aim of the article is to highlight the efforts of Indian scientists in this area with the…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-27 Tapomoy Guha Sarkar , Anjan A Sen

Cosmic evolution in the hydrogen content of the Universe through recombination and up to the end of reionization is expected to be revealed as subtle spectral features in the uniform extragalactic cosmic radio background. The redshift…

Instrumentation and Methods for Astrophysics · Physics 2015-01-20 Ravi Subrahmanyan , N. Udaya Shankar , Jonathan Pritchard , Harish K. Vedantham

A detection of the 21-cm signal power spectrum from the Epoch of Reionization is imminent, thanks to consistent advancements from telescopes such as LOFAR, MWA, and HERA, along with the development of SKA. In light of this progress, it is…

We explore the mean and fluctuating redshifted 21 cm signal in numerical simulations of cosmic reionization from the Cosmic Reionization On Computers (CROC) project. We find that the mean signal varies between about $\pm20\rm{mK}$. Most…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-29 Alexander A. Kaurov , Nickolay Y. Gnedin

We use cosmological simulations of reionization to predict the possible signal from the redshifted 21 cm line of neutral hydrogen in the pre-reionization era and to investigate the observability of this signal. We show that the separation…

Astrophysics · Physics 2009-11-10 Nickolay Y. Gnedin , Peter A. Shaver

During the epoch of reionization (EoR), the 21-cm signal allows direct observation of the neutral hydrogen (HI) in the intergalactic medium (IGM). In the post-reionization era, this signal instead probes HI in galaxies, which traces the…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-20 Sambit K. Giri , Michele Bianco , Timothée Schaeffer , Ilian T. Iliev , Garrelt Mellema , Aurel Schneider

We apply Bayesian statistics to perform model selection on different reionisation scenarios via the Multinest algorithm. Initially, we recover the results shown by 21CMMC for the parameter estimation of 21cmFAST models. We proceed to test…

Instrumentation and Methods for Astrophysics · Physics 2019-05-15 T. Binnie , J. R. Pritchard

We have used semi-numerical simulations of reionization to study the behaviour of the power spectrum of the EoR 21-cm signal in redshift space. We have considered two models of reionization, one which has homogeneous recombination (HR) and…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-05 Suman Majumdar , Somnath Bharadwaj , T. Roy Choudhury

Detecting the 21-cm hyperfine transition from neutral hydrogen in the intergalactic medium is our best probe for understanding the astrophysical processes driving the Epoch of Reionisation (EoR). The primary means for a detection of this…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-18 Bradley Greig , Yuan-Sen Ting , Alexander A. Kaurov

The EoR 21-cm signal is expected to become highly non-Gaussian as reionization progresses. This severely affects the error-covariance of the EoR 21-cm power spectrum which is important for predicting the prospects of a detection with…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-14 Rajesh Mondal , Somnath Bharadwaj , Suman Majumdar

21cm intensity mapping experiments aim to observe the diffuse neutral hydrogen (HI) distribution on large scales which traces the Cosmic structure. The Square Kilometre Array (SKA) will have the capacity to measure the 21cm signal over a…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-19 Laura Wolz , Filipe B. Abdalla , David Alonso , Chris Blake , Philip Bull , Tzu-Ching Chang , Pedro G. Ferreira , Cheng-Yu Kuo , Marios G. Santos , Richard Shaw

Observations with radio arrays that target the 21-cm signal originating from the early Universe suffer from a variety of systematic effects. An important class of these are reflections and spurious couplings between antennas. We apply a…

The redshifted $21$\,cm signal of neutral hydrogen can be used as a direct probe of the intergalactic medium during Cosmic Dawn\,(CD) and Epoch of Reionization\,(EoR). However, detecting this inherently weak signal has numerous challenges.…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-28 Samit Kumar Pal , Abhirup Datta , Aishrila Mazumder