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Intensity mapping of the HI 21 cm line and the CO 2.61 mm line from the epoch of reionization has emerged as powerful, complementary, probes of the high-redshift Universe. However, both maps and their cross-correlation are dominated by…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-11 Meng Zhou , Jianrong Tan , Yi Mao

Statistical observations of the Epoch of Reionization using the 21 cm line of neutral hydrogen have the potential to revolutionize our understanding of structure formation and the first luminous objects. However, these observations are…

Astrophysics · Physics 2008-11-26 Miguel F. Morales , Judd D. Bowman , Jacqueline N. Hewitt

The 21 cm bispectrum (BS) offers a powerful probe of the Epoch of Reionization (EoR), but its observational access is severely hindered by dominant astrophysical foregrounds. Considering Murchison Widefield Array (MWA) observations at…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-20 Sukhdeep Singh Gill , Khandakar Md Asif Elahi , Somnath Bharadwaj , Shiv K. Sethi , Akash Kumar Patwa

Future gravitational wave (GW) standard siren catalogues will probe the late-time expansion history of the Universe across redshift ranges largely inaccessible to traditional electromagnetic observations. To determine how effectively this…

Cosmology and Nongalactic Astrophysics · Physics 2026-05-27 Gourab Nandi , Anish Ghoshal , David F. Mota

Redshifted 21cm-line signal from neutral hydrogens in the intergalactic medium (IGM) gives a direct probe of the epoch of reionization (EoR). In this paper, we investigate the potential of the variance and skewness of the probability…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-31 Kenji Kubota , Shintaro Yoshiura , Hayato Shimabukuro , Keitaro Takahashi

Precision antenna calibration is required for mitigating the impact of foreground contamination in 21 cm cosmological radio surveys. One widely studied source of error is the effect of missing point sources in the calibration sky model;…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-19 Ntsikelelo Charles , Nicholas Kern , Gianni Bernardi , Landman Bester , Oleg Smirnov , Nicolas Fagnoni , Eloy de Lera Acedo

The accurate and precise removal of 21-cm foregrounds from Epoch of Reionization redshifted 21-cm emission data is essential if we are to gain insight into an unexplored cosmological era. We apply a non-parametric technique, Generalized…

The bispectrum is a 3-point statistic with the potential to provide additional information beyond power spectra analyses of survey datasets. Radio telescopes which broadly survey the 21cm emission from neutral hydrogen (HI) are a promising…

Cosmology and Nongalactic Astrophysics · Physics 2021-08-11 Steven Cunnington , Catherine Watkinson , Alkistis Pourtsidou

21-cm intensity mapping (IM) is a powerful technique to probe the large-scale distribution of neutral hydrogen (HI) and extract cosmological information such as the baryon acoustic oscillation feature. A key challenge lies in recovering the…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-24 Zitong Wang , Feng Shi , Le Zhang , Yanming Liu , Xiaoping Li , Shulei Ni , Ming Jiang , Xiaofan Ma

The first measurements of the 21 cm brightness temperature power spectrum from the epoch of reionization will very likely be achieved in the near future by radio interferometric array experiments such as the Hydrogen Epoch of Reionization…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-22 Xiaosheng Zhao , Yi Mao , Benjamin D. Wandelt

Radio-interferometric arrays require very precise calibration to detect the Epoch of Reionization 21-cm signal. A remarkably complete and accurate sky model is therefore needed in the patches of the sky used to perform the calibration.…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-13 Khandakar Md Asif Elahi , Samir Choudhuri , Nirupam Roy , Md Rashid , Philip Bull , Dharam Vir Lal

The GMRT reionization effort aims to map out the large scale structure of the Universe during the epoch of reionization (EoR). Removal of polarized Galactic emission is a difficult part of any 21 cm EoR program, and we present new upper…

The 21-cm brightness-temperature field of neutral hydrogen during the Epoch of Reionization and Cosmic Dawn is a rich source of cosmological and astrophysical information, primarily due to its significant non-Gaussian features. However, the…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-12 Bohdan Bidenko , Léon V. E. Koopmans , P. Daniel Meerburg

Measurement of redshifted 21-cm emission from neutral hydrogen promises to be the most effective method for studying the reionisation history of hydrogen and, indirectly, the first galaxies. These studies will be limited not by raw…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-24 Paul M. Geil , B. M. Gaensler , J. Stuart B. Wyithe

We measure several properties of the reionization process and the corresponding low-frequency 21-cm signal associated with the neutral hydrogen distribution, using a large volume, high resolution simulation of cosmic reionization. The…

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 present a novel computational approach for extracting weak signals, whose exact location and width may be unknown, from complex background distributions with an arbitrary functional form. We focus on datasets that can be naturally…

High Energy Physics - Experiment · Physics 2023-03-22 Abhijith Gandrakota , Amitabh Lath , Alexandre V. Morozov , Sindhu Murthy

Separating the cosmological redshifted 21-cm signal from foregrounds is a major challenge. We present the cross-correlation of the redshifted 21-cm emission from neutral hydrogen (HI) in the post-reionization era with the Ly-alpha forest as…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Tapomoy Guha Sarkar , Somnath Bharadwaj , Tirthankar Roy Choudhury , Kanan Datta

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

Radio interferometers, such as the Low-Frequency Array and the future Square Kilometre Array, are attempting to measure the spherically averaged 21-cm power spectrum from the Epoch of Reionization. Understanding of the dominant physical…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-01 Ivelin Georgiev , Garrelt Mellema , Sambit K. Giri , Rajesh Mondal