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Related papers: Twenty-one centimeter tomography with foregrounds

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A proposed method for dealing with foreground emission in upcoming 21-cm observations from the epoch of reionization is to limit observations to an uncontaminated window in Fourier space. Foreground emission can be avoided in this way,…

Cosmology and Nongalactic Astrophysics · Physics 2015-12-23 Hannes Jensen , Suman Majumdar , Garrelt Mellema , Adam Lidz , Ilian T. Iliev , Keri L. Dixon

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

We propose the HI 21-cm power spectrum from the post-reionization epoch as a probe of a cosmological model with decaying dark matter particles. The unstable particles are assumed to undergo a 2-body decay into a massless and massive…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-12 Mohit Yadav , Tapomoy Guha Sarkar

Neutral hydrogen (HI) $21$-cm intensity mapping (IM) is a promising probe of the large-scale structures in the Universe. However, a few orders of magnitude brighter foregrounds obscure the IM signal. Here we use the Tapered Gridded…

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

21cm-galaxy cross-correlation will play a key role in confirming the cosmological 21cm signal. We investigate which survey configurations detect the 21cm-LAE cross-correlation signal, and assess its ability to distinguish reionisation…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Anne Hutter , Caroline Heneka

All 21-cm signal experiments rely on electronic receivers that affect the data via both multiplicative and additive biases through the receiver's gain and noise temperature. While experiments attempt to remove these biases, the residuals of…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Keith Tauscher , David Rapetti , Bang D. Nhan , Alec Handy , Neil Bassett , Joshua Hibbard , David Bordenave , Richard F. Bradley , Jack O. Burns

We propose an all-digital telescope for 21 cm tomography, which combines key advantages of both single dishes and interferometers. The electric field is digitized by antennas on a rectangular grid, after which a series of Fast Fourier…

Astrophysics · Physics 2009-10-29 Max Tegmark , Matias Zaldarriaga

Cross-correlation between the redshifted 21 cm signal and Lyman-{\alpha} emitters (LAEs) is powerful tool to probe the Epoch of Reionization (EoR). Although the cross-power spectrum (PS) has an advantage of not correlating with foregrounds…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-25 S. Yoshiura , J. L. B. Line , K. Kubota , K. Hasegawa , K. Takahashi

In this work we present 21cmFirstCLASS, a modified version of 21cmFAST, the most popular code in the literature for computing the anisotropies of the 21-cm signal. Our code uses the public cosmic microwave background (CMB) Boltzmann code…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-29 Jordan Flitter , Ely D. Kovetz

In this paper, we propose a novel method to recover the 21cm global signal from the 21cm power spectrum using artificial neural networks (ANNs). The 21cm global signal is crucial for understanding cosmic evolution from the Dark Ages through…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Hayato Shimabukuro

We investigate the 21-cm signature that may arise from the intergalactic medium (IGM) prior to the epoch of full reionization (z>5). In scenarios in which the IGM is reionized by discrete sources of photoionizing radiation, the neutral gas…

Astrophysics · Physics 2009-10-28 Piero Madau , Avery Meiksin , Martin J. Rees

This paper explores the potential for statistical epoch of reionization (EOR) measurements using wide field radio observations. New developments in low frequency radio instrumentation and signal processing allow very sensitive EOR…

Astrophysics · Physics 2009-11-10 Miguel F. Morales , Jacqueline Hewitt

Experiments designed to measure the redshifted 21~cm line from the Epoch of Reionization (EoR) are challenged by strong astrophysical foreground contamination, ionospheric distortions, complex instrumental response and other different types…

The sky-averaged, or global, background of redshifted $21$ cm radiation is expected to be a rich source of information on cosmological reheating and reionizaton. However, measuring the signal is technically challenging: one must extract a…

Instrumentation and Methods for Astrophysics · Physics 2016-08-03 Tejaswi Venumadhav , Tzu-Ching Chang , Olivier Doré , Christopher M. Hirata

21cm tomography opens a window to directly study astrophysics and fundamental physics of early epochs in our Universe's history, the Epoch of Reionisation (EoR) and Cosmic Dawn (CD). Summary statistics such as the power spectrum omit…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 S. Neutsch , C. Heneka , M. Brüggen

We extend 21CMMC, a Monte Carlo Markov Chain sampler of 3D reionisation simulations, to perform parameter estimation directly on 3D light-cones of the cosmic 21cm signal. This brings theoretical analysis closer to the tomographic 21-cm…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-11 Bradley Greig , Andrei Mesinger

We compute the bispectra of the 21cm signal during the Epoch of Reionization for three different reionization scenarios that are based on a dark matter N-body simulation combined with a self-consistent, semi-numerical model of galaxy…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-08 Anne Hutter , Catherine A. Watkinson , Jacob Seiler , Pratika Dayal , Manodeep Sinha , Darren J. Croton

The cosmological 21 cm signal is one of the most promising avenues to study the Epoch of Reionization. One class of experiments aiming to detect this signal is global signal experiments measuring the sky-averaged 21 cm brightness…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-19 Stefan Heimersheim , Leiv Rønneberg , Henry Linton , Filippo Pagani , Anastasia Fialkov

Using a combination of N-body simulations, semi-analytic models and radiative transfer calculations, we have estimated the theoretical cross power spectrum between galaxies and the 21cm emission from neutral hydrogen during the epoch of…