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Related papers: Robust Foregrounds Removal for 21-cm Experiments

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The redshifted 21-cm monopole is expected to be a powerful probe of the epoch of the first stars and galaxies ($10<z<35$). The global 21-cm signal is sensitive to the thermal and ionization state of hydrogen gas and thus provides a tracer…

The measurements of the 21-cm brightness temperature fluctuations from the neutral hydrogen at the Epoch of Reionization (EoR) should inaugurate the next generation of cosmological observables. In this respect, many works have concentrated…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-10 Sebastien Clesse , Laura Lopez-Honorez , Christophe Ringeval , Hiroyuki Tashiro , Michel H. G. Tytgat

21 cm tomography is emerging as a promising probe of the cosmological dark ages and the epoch of reionization, as well as a tool for observational cosmology in general. However, serious sources of foreground contamination must be subtracted…

Astrophysics · Physics 2009-04-10 Adrian Liu , Max Tegmark , Matias Zaldarriaga

Measurements of the one-point probability distribution function and higher-order moments (variance, skewness, and kurtosis) of the high-redshift 21 cm fluctuations are among the most direct statistical probes of the non-Gaussian nature of…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Piyanat Kittiwisit , Judd D. Bowman , Steven G. Murray , Bharat K. Gehlot , Daniel C. Jacobs , Adam P. Beardsley

It is well-known that foreground subtraction in 21cm surveys removes large scale power. We investigate associated systematic biases. We show that removing line-of-sight fluctuations on large scales aliases into suppression of the 3D power…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Nada Petrovic , S. Peng Oh

With improving telescopes, it may now be possible to observe the Epoch of Reionization in multiple ways. We examine two of these observables - the excess light in the near-infrared background that may be due to high redshift stars and…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-19 Elizabeth R. Fernandez , Saleem Zaroubi , Ilian T. Iliev , Garrelt Mellema , Vibor Jelic

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 present new constraints on the 21cm Epoch of Reionization (EoR) power spectrum derived from 3 months of observing with a 32-antenna, dual-polarization deployment of the Donald C. Backer Precision Array for Probing the Epoch of…

The \hi 21 cm transition line is expected to be an important probe into the cosmic dark ages and epoch of reionization. Foreground source removal is one of the principal challenges for the detection of this signal. This paper investigates…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 A. Datta , J. D. Bowman , C. L. Carilli

We investigate a number of potential foregrounds for an ambitious goal of future radio telescopes such as the Square Kilometer Array (SKA) and Low Frequency Array (LOFAR): spatial tomography of neutral gas at high redshift in 21cm emission.…

Astrophysics · Physics 2009-11-07 S. Peng Oh , Katherine J. Mack

The precise measurement of the sky-averaged HI absorption signal between 50 and 200 MHz is the primary goal of global 21-cm cosmology. This measurement has the potential to unravel the underlying physics of cosmic structure formation and…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-04 Emma Shen , Dominic Anstey , Marta Spinelli , Eloy de Lera Acedo , Anastasia Fialkov

The birth of the first luminous sources and the ensuing epoch of reionization are best studied via the redshifted 21-cm emission line, the signature of the first two imprinting the last. In this work we present a fully-Bayesian method,…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-27 G. Bernardi , J. T. L. Zwart , D. Price , L. J. Greenhill , A. Mesinger , J. Dowell , T. Eftekhari , S. W. Ellingson , J. Kocz , F. Schinzel

We propose a continuous wavelet transform based non-parametric foreground subtraction method for the detection of redshifted 21 cm signal from the epoch of reionization. This method works based on the assumption that the foreground spectra…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Junhua Gu , Haiguang Xu , Jingying Wang , Tao An , Wen Chen

The light of the first astrophysical objects is expected to leave an imprint on the global 21-cm signal as it heats, excites, and ionizes neutral hydrogen. This dependence on early astrophysics introduces significant uncertainties in…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-06 Omer Zvi Katz

Extracting the neutral hydrogen (HI) signal is a great challenge for cosmological 21cm experiments, both the astrophysical foregrounds and the receiver noise are typically several orders of magnitude greater than the 21cm signal. However,…

Cosmology and Nongalactic Astrophysics · Physics 2019-06-14 Qizhi Huang , Fengquan Wu , Reza Ansari , Xuelei Chen

Upper limits from the current generation of interferometers targeting the 21-cm signal from high redshifts have recently begun to rule out physically realistic, though still extreme, models of the Epoch of Reionization (EoR). While…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-08 Jordan Mirocha , Julian B. Muñoz , Steven R. Furlanetto , Adrian Liu , Andrei Mesinger

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…

Measurements of the 21cm line emission by residual cosmic hydrogen after reionization can be used to trace the power spectrum of density perturbations through a significant fraction of the observable volume of the Universe. We show that a…

Astrophysics · Physics 2009-06-23 Abraham Loeb , Stuart Wyithe

The 21 cm signal arising from fluctuations in the neutral hydrogen field, and its cross-correlation with other tracers of cosmic density, are promising probes of the high-redshift Universe. In this study, we assess the potential of the 21…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-26 Barun Maity

Detecting neutral Hydrogen (H\,{\sc i}) via the 21~cm line emission from the intergalactic medium at $z\gtrsim 6$ has been identified as one of the most promising probes of the epoch of cosmic reionization -- a major phase transition of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-04 Nithyanandan Thyagarajan , Chris Carilli , Bojan Nikolic
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