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相关论文: Recovery of 21 cm intensity maps with sparse compo…

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Cosmic microwave background radiation (CMB) observations are unavoidably contaminated by emission from various extra-galactic foregrounds, which must be removed to obtain reliable measurements of the cosmological signal. In this paper, we…

The 21-cm global signal is obscured by very bright galactic and extra galactic foreground emissions. Typical single-spectrum fit (SSF) based methods for foreground/signal separation can result in biased estimates of the cosmological signal…

宇宙学与河外天体物理 · 物理学 2025-06-27 Yordan D. Ignatov , Jonathan R. Pritchard

Weak gravitational lensing by the intervening large-scale structure of the Universe induces high-order correlations in the cosmic microwave background (CMB) temperature and polarization fields. We construct minimum variance estimators of…

天体物理学 · 物理学 2008-11-26 Wayne Hu , Takemi Okamoto

Simulated observations of a $10\dg \times 10\dg$ field by the Microwave Anisotropy Probe (MAP) are analysed in order to separate cosmic microwave background (CMB) emission from foreground contaminants and instrumental noise and thereby…

天体物理学 · 物理学 2009-10-31 A. W. Jones , M. P. Hobson , A. N. Lasenby

Detection of magnetic-type ($B$-type) polarization in the Cosmic Microwave Background (CMB) radiation plays a crucial role in probing the relic gravitational wave (RGW) background. In this paper, we propose a new method to deconstruct a…

宇宙学与河外天体物理 · 物理学 2015-03-17 Wen Zhao , Deepak Baskaran

The 21 cm intensity mapping provides a promising probe of the large-scale structure. Astrophysical foregrounds, as the main source of contamination to the cosmological 21 cm signal, persist in a wedge-like region of Fourier space due to the…

宇宙学与河外天体物理 · 物理学 2026-02-04 Kaifeng Yu , Xin Wang

The full sky cosmic microwave background polarization field can be decomposed into 'electric' and 'magnetic' components. Working in harmonic space we construct window functions that allow clean separation of the electric and magnetic modes…

天体物理学 · 物理学 2009-11-06 Antony Lewis , Anthony Challinor , Neil Turok

Multi-frequency observations are needed to separate the CMB from foregrounds and accurately extract cosmological information from the data. The Analytical Blind Separation (ABS) method is dedicated to extracting the CMB power spectrum from…

宇宙学与河外天体物理 · 物理学 2021-03-22 Larissa Santos , Jian Yao , Le Zhang , Shamik Ghosh , Pengjie Zhang , Wen Zhao , Thyrso Villela , Jiming Chen , Jacques Delabrouille

To recover the 21 cm hydrogen line, it is essential to separate the cosmological signal from the much stronger foreground contributions at radio frequencies. The BINGO radio telescope is designed to measure the 21 cm line and detect BAOs…

We study the limits of accuracy for weak lensing maps of dark matter using diffuse 21-cm radiation from the pre-reionization epoch using simulations. We improve on previous "optimal" quadratic lensing estimators by using shear and…

天体物理学 · 物理学 2009-11-13 Tingting Lu , Ue-Li Pen

Abreg: We investigate the impact of polarized foreground emission on the performances of future CMB experiments in measuring the tensor-to-scalar ratio r. We design a component separation pipeline, based on the Smica method, aimed at…

宇宙学与河外天体物理 · 物理学 2015-05-13 Marc Betoule , E. Pierpaoli , J. Delabrouille , M. Le Jeune , Jean-François Cardoso

[Abridged] We have produced a cleaned map of the Wilkinson Microwave Anisotropy Probe (WMAP) 3-year data using an improved foreground subtraction technique. We perform an internal linear combination (ILC) to subtract the Galactic foreground…

天体物理学 · 物理学 2008-11-26 Chan-Gyung Park , Changbom Park , J. Richard Gott

We implement and further refine the recently proposed method (Kashlinsky, Hern\'andez-Monteagudo & Atrio-Barandela, 2001 - KHA) for a time efficient extraction of the power spectrum from future cosmic microwave background (CMB) maps. The…

天体物理学 · 物理学 2009-11-07 C. Hernandez-Monteagudo , A. Kashlinsky , F. Atrio-Barandela

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…

[Abridged] The spatially averaged global spectrum of the redshifted 21cm line has generated much experimental interest, for it is potentially a direct probe of the Epoch of Reionization and the Dark Ages. Since the cosmological signal here…

宇宙学与河外天体物理 · 物理学 2013-06-07 Adrian Liu , Jonathan R. Pritchard , Max Tegmark , Abraham Loeb

We have studied the implications of high sensitivity polarization measurements of objects from the WMAP point source catalogue made using the VLA at 8.4, 22 and 43 GHz. The fractional polarization of sources is almost independent of…

宇宙学与河外天体物理 · 物理学 2015-05-18 R. A. Battye , I. W. A. Browne , M. W. Peel , N. J. Jackson , C. Dickinson

21 cm intensity mapping has emerged as a promising technique to map the large-scale structure of the Universe, at redshifts $z$ from 1 to 10. Unfortunately, many of the key cross-correlations with the cosmic microwave background and…

宇宙学与河外天体物理 · 物理学 2018-11-20 Hong-Ming Zhu , Ue-Li Pen , Yu Yu , Xuelei Chen

In our previous study, we introduced a machine-learning technique, namely CMBFSCNN, for the removal of foreground contamination in cosmic microwave background (CMB) polarization data. This method was successfully employed on actual…

宇宙学与河外天体物理 · 物理学 2024-08-19 Ye-Peng Yan , Si-Yu Li , Guo-Jian Wang , Zirui Zhang , Jun-Qing Xia

The long wavelength modes lost to bright foregrounds in the interferometric 21-cm surveys can partially be recovered using a forward modeling approach that exploits the non-linear coupling between small and large scales induced by…

宇宙学与河外天体物理 · 物理学 2021-10-27 Chirag Modi , Martin White , Emanuele Castorina , Anže Slosar

Delensing is an increasingly important technique to reverse the gravitational lensing of the cosmic microwave background (CMB) and thus reveal primordial signals the lensing may obscure. We present a first demonstration of delensing on…

宇宙学与河外天体物理 · 物理学 2016-10-12 Patricia Larsen , Anthony Challinor , Blake D. Sherwin , Daisy Mak