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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

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

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 redshifted 21-cm signal of neutral Hydrogen is a promising probe into the period of evolution of our Universe when the first stars were formed (Cosmic Dawn), to the period where the entire Universe changed its state from being…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-26 Madhurima Choudhury , Atrideb Chatterjee , Abhirup Datta , Tirthankar Roy Choudhury

Direct detection of regions of ionized hydrogen (HII) has been suggested as a promising probe of cosmic reionization. Observing the redshifted 21-cm signal of hydrogen from the epoch of reionization (EoR) is a key scientific driver behind…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-20 Paul M. Geil , Simon J. Mutch , Gregory B. Poole , Alan R. Duffy , Andrei Mesinger , J. Stuart B. Wyithe

New low frequency radio telescopes currently being built open up the possibility of observing the 21-cm radiation before the Epoch of Reionization in the future, in particular at redshifts 200 > z > 30, also known as the dark ages. At these…

Cosmology and Nongalactic Astrophysics · Physics 2010-01-03 Rishi Khatri , Benjamin D. Wandelt

The non-Gaussian nature of the epoch of reionization (EoR) 21-cm signal has a significant impact on the error variance of its power spectrum $P({\bf \textit{k}})$. We have used a large ensemble of semi-numerical simulations and an…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-26 Rajesh Mondal , Somnath Bharadwaj , Suman Majumdar

We discuss absolute calibration strategies for Phase I of the Hydrogen Epoch of Reionization Array (HERA), which aims to measure the cosmological 21 cm signal from the Epoch of Reionization (EoR). HERA is a drift-scan array with a 10 degree…

21 cm Epoch of Reionization observations promise to transform our understanding of galaxy formation, but these observations are impossible without unprecedented levels of instrument calibration. We present end-to-end simulations of a full…

Instrumentation and Methods for Astrophysics · Physics 2016-06-09 N. Barry , B. Hazelton , I. Sullivan , M. F. Morales , J. C. Pober

We present an analysis of Epoch of Reionization data from Phase II of the Murchison Widefield Array using the \texttt{simpleDS} delay spectrum pipeline. Prior work analyzed the same observations using the FHD/$\varepsilon$ppsilon imaging…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-05 Matthew Kolopanis , Jonathan Pober , Daniel C. Jacobs , Samantha McGraw

Direct detection of the Epoch of Reionization (EoR) via the red-shifted 21-cm line will have unprecedented implications on the study of structure formation in the infant Universe. To fulfill this promise, current and future 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-27 Abhik Ghosh , Florent Mertens , Leon V. E. Koopmans

Measurements of the Epoch of Reionization (EoR) 21-cm signal hold the potential to constrain models of reionization. In this paper we consider a reionization model with three astrophysical parameters namely (1) the minimum halo mass which…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-18 Abinash Kumar Shaw , Somnath Bharadwaj , Rajesh Mondal

There is growing interest in using 3-dimensional neutral hydrogen mapping with the redshifted 21 cm line as a cosmological probe, as it has been argued to have a greater long-term potential than the cosmic microwave background. However, its…

Astrophysics · Physics 2008-11-26 Yi Mao , Max Tegmark , Matthew McQuinn , Matias Zaldarriaga , Oliver Zahn

We present techniques for bridging the gap between idealized inverse covariance weighted quadratic estimation of 21 cm power spectra and the real-world challenges presented universally by interferometric observation. By carefully evaluating…

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

In order to study the "Cosmic Dawn" and the Epoch of Reionization with 21 cm tomography, we need to statistically separate the cosmological signal from foregrounds known to be orders of magnitude brighter. Over the last few years, we have…

The nature of dark matter sets the timeline for the formation of first collapsed halos and thus affects the sources of reionization. Here, we consider two different models of dark matter: cold dark matter (CDM) and thermal warm dark matter…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-31 Anchal Saxena , Suman Majumdar , Mohd Kamran , Matteo Viel

Efforts are being made to observe the 21-cm signal from the 'cosmic dawn' using sky-averaged observations with individual radio dipoles. In this paper, we develop a model of the observations accounting for the 21-cm signal, foregrounds, and…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-26 Geraint J. A. Harker , Jonathan R. Pritchard , Jack O. Burns , Judd D. Bowman

We investigate the sensitivity of the 21cm power spectrum from cosmic dawn and the epoch of reionization to models of free-streaming dark radiation (parameterized through $N_{\rm eff}$) and interacting dark radiation-dark matter models…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-22 Hugo Plombat , Théo Simon , Jordan Flitter , Vivian Poulin

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…