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Related papers: Foregrounds for redshifted 21 cm studies of reioni…

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We show how cross-correlating a high redshift external tracer field, such as the 21cm neutral hydrogen distribution and product maps involving Cosmic Microwave Background (CMB) temperature and polarisation fields, that probe mixed…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-07 D. Munshi , P. S. Corasaniti , P. Coles , A. Heavens , S. Pandolfi

Direct detection of the Dark Ages and the Epoch of Reionization (EOR) is among the main scientific objectives of all current and future low-frequency radio facilities. In this paper we summarize and discuss recent results, based on…

Astrophysics · Physics 2008-11-26 Ilian T. Iliev , Garrelt Mellema , Ue-Li Pen , Paul R. Shapiro

The 21 cm line provides a powerful probe of astrophysics and cosmology at high redshifts, but unlocking the potential of this probe requires the robust mitigation of foreground contaminants that are typically several orders of magnitude…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-25 Adrian Liu , Aaron R. Parsons , Cathryn M. Trott

We develop an effective perturbation theory (and, equivalently, a bias expansion) for the inhomogeneous 21cm radiation field from reionization. Using large-scale simulations of cosmological reionization, we find that this expansion…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-20 Matthew McQuinn , Anson D'Aloisio

We study the behavior of internal signal chain reflections and antenna cross coupling as systematics for 21 cm cosmological surveys. We outline the mathematics for how these systematics appear in interferometric visibilities and describe…

Instrumentation and Methods for Astrophysics · Physics 2019-10-28 Nicholas S. Kern , Aaron R. Parsons , Joshua S. Dillon , Adam E. Lanman , Nicolas Fagnoni , Eloy de Lera Acedo

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

Foreground removal presents a significant obstacle in both current and forthcoming intensity mapping surveys. While numerous techniques have been developed that show promise in simulated datasets, their efficacy often diminishes when…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-14 Jiacheng Ding , Xin Wang , Ue-Li Pen , Xiao-Dong Li

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

Detecting and characterizing the Epoch of Reionization and Cosmic Dawn via the redshifted 21-cm hyperfine line of neutral hydrogen will revolutionize the study of the formation of the first stars, galaxies, black holes and intergalactic gas…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 F. G. Mertens , A. Ghosh , L. V. E. Koopmans

We investigate the implications of interference detection for experiments that are pursuing a detection of the redshifted 21-cm signals from the Epoch of Reionization. Interference detection causes samples to be sporadically flagged and…

Instrumentation and Methods for Astrophysics · Physics 2019-03-13 A. R. Offringa , F. Mertens , L. V. E. Koopmans

Observation of redshifted 21-cm signal from the Epoch of Reionization (EoR) is challenging due to contamination from the bright foreground sources that exceed the signal by several orders of magnitude. The removal of this very high…

We present new calculations of the evolving UV background out to the epoch of cosmological reionization and make predictions for the amount of GeV gamma-ray attenuation by electron-positron pair production. Our results are based on recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-13 Rudy C. Gilmore , Piero Madau , Joel R. Primack , Rachel S. Somerville , Francesco Haardt

Upcoming experiments such as the SKA will provide huge quantities of data. Fast modelling of the high-redshift 21cm signal will be crucial for efficiently comparing these data sets with theory. The most detailed theoretical predictions…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-26 William D. Jennings , Catherine A. Watkinson , Filipe B. Abdalla , Jason D. McEwen

Observation of the 21cm line signal from neutral hydrogen during the Epoch of Reionization is challenging due to extremely bright Galactic and extragalactic foregrounds and complicated instrumental calibration. A reasonable approach for…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-12 S. Yoshiura , K. Ichiki , B. Pindor , K. Takahashi , H. Tashiro , C. M. Trott

We use the latest multi-redshift ($z=6.5-8.7$) upper limits on the 21-cm signal from the Murchison Widefield Array (MWA) to explore astrophysical models which are inconsistent with the data. These upper limits are achieved using 298 h of…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-25 Bradley Greig , Cathryn M. Trott , Nichole Barry , Simon J. Mutch , Bart Pindor , Rachel L. Webster , J. Stuart B. Wyithe

21 cm intensity mapping (HI IM) can efficiently map large cosmic volumes with good redshift resolution, but systematics and foreground contamination pose major challenges for extracting accurate cosmological information. Cross-correlation…

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

The cosmological global (sky-averaged) 21-cm signal is a powerful tool to probe the evolution of the intergalactic medium (IGM) in high-redshift Universe ($z \leq 6$). One of the biggest observational challenges is to remove the foreground…

Instrumentation and Methods for Astrophysics · Physics 2018-11-14 Bang D. Nhan , Richard F. Bradley , Jack O. Burns

The redshifted 1420 MHz emission from the HI in unresolved damped Lyman-\alpha clouds at high z will appear as a background radiation in low frequency radio observations. This holds the possibility of a new tool for studying the universe at…

Astrophysics · Physics 2009-10-31 Somnath Bharadwaj , Biman B. Nath , Shiv K. Sethi

A detection of the 21 cm signal can provide a unique window of opportunity for uncovering complex astrophysical phenomena at the epoch of reionization and placing constraints on cosmology at high redshifts, which are usually elusive to…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-21 Danial Baradaran , Boryana Hadzhiyska , Martin J. White , Noah Sailer