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The epoch of reionization power spectrum is expected to evolve strongly with redshift, and it is this variation with cosmic history that will allow us to begin to place constraints on the physics of reionization. The primary obstacle to the…

A number of experiments are currently working towards a measurement of the 21 cm signal from the Epoch of Reionization. Whether or not these experiments deliver a detection of cosmological emission, their limited sensitivity will prevent…

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 light-cone (LC) anisotropy arises due to cosmic evolution of the cosmic dawn 21-cm signal along the line-of-sight (LoS) axis of the observation volume. The LC effect makes the signal statistically non-ergodic along the LoS axis. The…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-26 Abinash Kumar Shaw , Raghunath Ghara , Saleem Zaroubi , Rajesh Mondal , Garrelt Mellema , Florent Mertens , Léon V. E. Koopmans , Benoît Semelin

We apply for the first time Gaussian Process Regression (GPR) as a foreground removal technique in the context of single-dish, low redshift HI intensity mapping, and present an open-source Python toolkit for doing so. We use MeerKAT and…

Cosmology and Nongalactic Astrophysics · Physics 2021-10-05 Paula S. Soares , Catherine A. Watkinson , Steven Cunnington , Alkistis Pourtsidou

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

We quantitatively investigate the possibility of detecting baryonic acoustic oscillations (BAO) using single-dish 21cm intensity mapping observations in the post-reionization era. We show that the telescope beam smears out the isotropic BAO…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Francisco Villaescusa-Navarro , David Alonso , Matteo Viel

Cosmic Dawn (CD) and Epoch of Reionization (EoR) are epochs of the Universe which host invaluable information about the cosmology and astrophysics of X-ray heating and hydrogen reionization. Radio interferometric observations of the 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-10 Anchal Saxena , Alex Cole , Simon Gazagnes , P. Daniel Meerburg , Christoph Weniger , Samuel J. Witte

A critical challenge in the observation of the redshifted 21-cm line is its separation from bright Galactic and extragalactic foregrounds. In particular, the instrumental leakage of polarized foregrounds, which undergo significant Faraday…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-18 C. D. Nunhokee , G. Bernardi , S. A. Kohn , J. E. Aguirre , N. Thyagarajan , J. S. Dillon , G. Foster , T. L. Grobler , J. Z. E. Martinot , A. R. Parsons

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 overwhelming foreground causes severe contamination on the detection of 21-cm signal during the Epoch of Reionization (EoR). Among various foreground components, the Galactic free-free emission is less studied, so that its impact on the…

Astrophysics of Galaxies · Physics 2020-07-07 Xiaoli Lian , Haiguang Xu , Dongchao Zheng , Zhenghao Zhu , Dan Hu

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 21-cm signal of neutral hydrogen is a sensitive probe of the Epoch of Reionization (EoR) and Cosmic Dawn. Currently operating radio telescopes have ushered in a data-driven era of 21-cm cosmology, providing the first constraints on the…

Cosmology and Nongalactic Astrophysics · Physics 2020-06-10 Aviad Cohen , Anastasia Fialkov , Rennan Barkana , Raul Monsalve

The residual gain errors add to the systematics of the radio interferometric observations. In case of the high dynamic range observations, these systematic effects dominates over the thermal noise of the observation. In this work, we…

Instrumentation and Methods for Astrophysics · Physics 2021-01-13 Jais Kumar , Prasun Dutta , Nirupam Roy

A first statistical detection of the 21-cm Epoch of Reionization (EoR) is on the horizon, as cosmological volumes of the Universe become accessible via the adoption of low-frequency interferometers. We explore the impact which non-identical…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-01 A. Chokshi , N. Barry , J. L. B. Line , C. H. Jordan , B. Pindor , R. L. Webster

We explore methods for robust estimation of the 21 cm signal from the Epoch of Reionisation (EoR). A Kernel Density Estimator (KDE) is introduced for measuring the spatial temperature fluctuation power spectrum from the EoR. The KDE…

Enlightening our understanding of the first galaxies responsible for driving reionisation requires detecting the 21-cm signal from neutral hydrogen. Interpreting the wealth of information embedded in this signal requires Bayesian inference.…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-22 Bradley Greig , David Prelogović , Yuxiang Qin , Yuan-Sen Ting , Andrei Mesinger

The 21cm-galaxy cross-power spectrum is expected to be one of the promising probes of the Epoch of Reionization (EoR), as it could offer information about the progress of reionization and the typical scale of ionized regions at different…

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

During the Epoch of Reionization (EoR), the ultraviolet radiation from the first stars and galaxies ionised the neutral hydrogen of the intergalactic medium, which can emit radiation through its 21 cm hyperfine transition. This 21 cm signal…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-27 Ivelin Georgiev , Adélie Gorce , Garrelt Mellema