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The 21 cm brightness temperature during the Epoch of Reionisation is widely modelled using semi-numeric simulations, used for their computational speed and flexibility in testing astrophysical and cosmological parameters. However, it is…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-17 Jennifer Feron , Emma Chapman

21 cm intensity mapping has emerged as a promising technique to map the large-scale structure of the Universe. However, the presence of foregrounds with amplitudes orders of magnitude larger than the cosmological signal constitutes a…

Cosmology and Nongalactic Astrophysics · Physics 2020-09-30 Isabella P. Carucci , Melis O. Irfan , Jérôme Bobin

One of the main challenges facing upcoming CMB experiments will be to distinguish the cosmological signal from foreground contamination. We present a comprehensive treatment of this problem and study how foregrounds degrade the accuracy…

Astrophysics · Physics 2009-10-07 Max Tegmark , Daniel J. Eisenstein , Wayne Hu , Angelica de Oliveira-Costa

The ability to subtract foreground contamination from low-frequency observations is crucial to reveal the underlying 21 cm signal. The traditional line-of-sight methods can deal with the removal of diffuse emission and unresolved point…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Xiao-Chun Mao

Global (i.e. sky-averaged) $21$~cm signal experiments can measure the evolution of the universe from the Cosmic Dawn to the Epoch of Reionization. These measurements are challenged by the presence of bright foreground emission that can be…

Cosmology and Nongalactic Astrophysics · Physics 2019-09-25 Marta Spinelli , Gianni Bernardi , Mario G. Santos

Direct detection of the Epoch of Reionization via the redshifted 21-cm line will have unprecedented implications on the study of structure formation in the early Universe. To fulfill this promise current and future 21-cm experiments will…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-22 F. Mertens , A. Ghosh , L. V. E. Koopmans

Astrophysical foreground substraction is crucial to retrieve the cosmic microwave background (CMB) polarization out of the observed data. Recent efforts have been carried out towards the development of a minimally informed component…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-08 Clément Leloup , Magdy Morshed , Arianna Rizzieri

We study the effects of astrophysical foregrounds on the ability of CMB B-mode polarization experiments to constrain the primordial tensor-to-scalar ratio, r. To clean the foreground contributions we use parametric, maximum likelihood…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-20 Josquin Errard , Radek Stompor

21cm emission from residual neutral hydrogen after the epoch of reionization can be used to trace the cosmological power spectrum of density fluctuations. Using a Fisher matrix formulation, we provide a detailed forecast of the constraints…

Astrophysics · Physics 2009-11-13 Eli Visbal , Abraham Loeb , Stuart Wyithe

A key challenge for current and upcoming CMB lensing measurements is their sensitivity to biases from extragalactic foregrounds, such as Sunyaev-Zeldovich (SZ) signals or cosmic infrared background emission. Several methods have been…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-02 Omar Darwish , Blake D. Sherwin , Noah Sailer , Emmanuel Schaan , Simone Ferraro

Contamination by polarized foregrounds is one of the biggest challenges for future polarized cosmic microwave background (CMB) surveys and the potential detection of primordial $B$-modes. Future experiments, such as Simons Observatory (SO)…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-12 Carlos Hervías-Caimapo , Anna Bonaldi , Michael L. Brown , Kevin M. Huffenberger

We present a new model of the microwave sky in polarization that can be used to simulate data from CMB polarization experiments. We exploit the most recent results from the Planck satellite to provide an accurate description of the diffuse…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-31 Carlos Hervías-Caimapo , Anna Bonaldi , Michael L. Brown

We use a simple model to investigate the effect of polarized Galactic foreground emission on the ability of planned CMB missions to detect and model CMB polarization. Emission from likely polarized sources (synchrotron and spinning dust)…

Astrophysics · Physics 2007-05-23 A. Kogut , G. Hinshaw

We analyze the possibility of delensing CMB polarization maps using foreground weak lensing (WL) information. We build an estimator of the CMB lensing potential out of optimally combined projected potential estimators to different source…

Astrophysics · Physics 2008-11-26 Laura Marian , Gary M. Bernstein

Mechanisms have been proposed that might rotate the linear polarization of the cosmic microwave background (CMB) as it propagates from the surface of last scatter. In the simplest scenario, the rotation will be uniform across the sky, but…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-02 Vera Gluscevic , Marc Kamionkowski , Asantha Cooray

Templates for polarised emission from Galactic foregrounds at frequencies relevant to Cosmic Microwave Background (CMB) polarisation experiments are obtained by modelling the Galactic Magnetic Field (GMF) on large scales. This work extends…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-21 C. N. Clark , C. R. Contaldi , C. J. MacTavish

We describe a new multi-scale deconvolution algorithm that can also be used in multi-frequency mode. The algorithm only affects the minor clean loop. In single-frequency mode, the minor loop of our improved multi-scale algorithm is over an…

Instrumentation and Methods for Astrophysics · Physics 2017-08-02 A. R. Offringa , O. Smirnov

Recognizing the impact of contamination from weak gravitational lensing B-modes induced by Large Scale Structure, we examine delensing methods to enhance sensitivity to the tensor-to-scalar ratio $r$ in primordial B-mode detection…

Cosmology and Nongalactic Astrophysics · Physics 2025-11-27 Wen-Zheng Chen , Yang Liu , Siyu Li , Bin Hu , Hong Li