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The brightness temperature fluctuations in the 21 cm background related to neutral Hydrogen distribution provide a probe of physics related to the era of reionization when the intergalactic medium changed from a completely neutral to a…

Astrophysics · Physics 2009-06-15 Asantha Cooray

Improvements in current instruments and the advent of next-generation instruments will soon push observational 21 cm cosmology into a new era, with high significance measurements of both the power spectrum and the mean ("global") signal of…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-08 Adrian Liu , Aaron R. Parsons

Radio interferometers designed to probe the 21cm signal from Cosmic Dawn and the Epoch of Reionisation must contend with systematic effects that make it difficult to achieve sufficient dynamic range to separate the 21cm signal from…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-24 Fraser Kennedy , Philip Bull , Michael Wilensky , Jacob Burba , Samir Choudhuri

Observations of the 21cm Epoch of Reionization (EoR) signal are dominated by Galactic and extragalactic foregrounds. The need for foreground removal has led to the development of two main techniques, often referred to as "foreground…

We present a comprehensive simulation-based study of the BayesEoR code for 21 cm power spectrum recovery when analytically marginalizing over foreground parameters. To account for covariance between the 21 cm signal and contaminating…

Instrumentation and Methods for Astrophysics · Physics 2023-02-09 Jacob Burba , Peter H. Sims , Jonathan C. Pober

The 21-cm forest, comprising narrow absorption features imprinted on the radio spectra of high-redshift radio-loud quasars by intervening neutral hydrogen, offers a uniquely sensitive probe of the thermal state of the neutral intergalactic…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-25 Sameer K. Patil , Tomáš Šoltinský , Soumak Maitra , Girish Kulkarni

We propose a deep learning analyzing technique with convolutional neural network (CNN) to predict the evolutionary track of the Epoch of Reionization (EoR) from the 21-cm differential brightness temperature tomography images. We use…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Yungi Kwon , Sungwook E. Hong , Inkyu Park

Measurements of 21 cm Epoch of Reionization (EoR) structure are subject to systematics originating from both the analysis and the observation conditions. Using 2013 data from the Murchison Widefield Array (MWA), we show the importance of…

Numerous experiments have been designed to investigate the Cosmic Dawn (CD) and Epoch of Reionization (EoR) by examining redshifted 21-cm emissions from neutral hydrogen. Detecting the global spectrum of redshifted 21-cm signals is…

Instrumentation and Methods for Astrophysics · Physics 2025-04-08 Feiyu Zhao , Quan Guo , Qian Zheng , Ruxi Liang , Pengfei Zhang , Yajun Wu , Junhua Gu , Zhao Yang , Yun Yu , Yan Huang , Tianyang Liu

Measurement of the global 21-cm signal during Cosmic Dawn (CD) and the Epoch of Reionization (EoR) is made difficult by bright foreground emission which is 2-5 orders of magnitude larger than the expected signal. Fitting for a…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-20 Michael Pagano , Peter Sims , Adrian Liu , Dominic Anstey , Will Handley , Eloy De Lera Acedo

We introduce simulations aimed at assessing how well weak gravitational lensing of 21cm radiation from the Epoch of Reionization ($z \sim 8$) can be measured by an SKA-like radio telescope. A simulation pipeline has been implemented to…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-21 Alessandro Romeo , R. Benton Metcalf , Alkistis Pourtsidou

A limiting systematic effect in 21-cm interferometric experiments is the chromaticity due to the coupling between the sky and the instrument. This coupling is sourced by the instrument primary beam; therefore it is important to know the…

Instrumentation and Methods for Astrophysics · Physics 2022-06-22 Ainulnabilah Nasirudin , David Prelogovic , Steven G. Murray , Andrei Mesinger , Gianni Bernardi

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…

The cosmic 21-cm signal will bring data-driven advances to studies of the Cosmic Dawn (CD) and Epoch of Reionization (EoR). Radio telescopes such as the SKA will eventually map the HI fluctuations over the first billion years - the majority…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-08 David Prelogović , Andrei Mesinger

We examine the impact of baryon-dark matter relative velocities on intergalactic small-scale structure and the 21 cm signal during reionization. Streaming velocities reduced clumping in the intergalactic medium (IGM) on mass scales of $\sim…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-18 Christopher Cain , Anson D'Aloisio , Vid Iršič , Matthew McQuinn , Hy Trac

The recent low value of Planck (2016) integrated optical depth to Thomson scattering suggests that the reionization occurred fairly suddenly, disfavoring extended reionization scenarios. This will have a significant impact on the 21cm power…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-27 Sultan Hassan , Romeel Dave , Kristian Finlator , Mario G. Santos

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

We use information theory to derive fundamental limits on the capacity to calibrate next-generation radio interferometers, and measure parameters of point sources for instrument calibration, point source subtraction, and data deconvolution.…

Instrumentation and Methods for Astrophysics · Physics 2012-12-11 Cathryn M. Trott , Randall B. Wayth , Steven J. Tingay

The 21 cm emission of neutral hydrogen is the most promising probe of the epoch of reionization(EoR). In the next few years, the SKA pathfinders will provide statistical measurements of this signal. Numerical simulations predicting these…

Astrophysics · Physics 2009-11-13 S. Baek , P. Di Matteo , B. Semelin , F. Combes , Y. Revaz

In the most distant reaches of the Universe, the 21-cm hyperfine transition in neutral hydrogen provides one of the only available tracers of large-scale structure. A number of instruments have been working and planned to measure the 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2023-03-15 Teppei Minoda , Shohei Saga , Tomo Takahashi , Hiroyuki Tashiro , Daisuke Yamauchi , Shuichiro Yokoyama , Shintaro Yoshiura
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