中文
相关论文

相关论文: Foreground separation using a flexible maximum-ent…

200 篇论文

We apply the iterative Expectation-Maximization algorithm (EM) to estimate the power spectrum of the CMB from multifrequency microwave maps. In addition, we are also able to provide a reconstruction of the CMB map. By assuming that the…

天体物理学 · 物理学 2009-11-07 E. Martinez-Gonzalez , J. M. Diego , P. Vielva , J. Silk

The cosmic microwave background $B$-mode signal is potentially weaker than the diffuse Galactic foregrounds over most of the sky at any frequency. A common method of separating the CMB from these foregrounds is via pixel-based…

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…

宇宙学与河外天体物理 · 物理学 2012-04-20 Josquin Errard , Radek Stompor

One of the main obstacles in extracting the Cosmic Microwave Background (CMB) signal from observations in the mm-submm range is the foreground contamination by emission from galactic components: mainly synchrotron, free-free and thermal…

天体物理学 · 物理学 2008-12-18 H. U. Norgaard-Nielsen , H. E. Jorgensen

We review aspects of Cosmic Microwave Background (CMB) spectral distortions which do not appear to have been fully explored in the literature. In particular, implications of recent evidences of heating of the intergalactic medium (IGM) by…

宇宙学与河外天体物理 · 物理学 2016-04-13 G. De Zotti , M. Negrello , G. Castex , A. Lapi , M. Bonato

Measurements of the cosmic microwave background (CMB) allow high precision observation of the Last Scattering Surface at redshift $z\sim$1100. After the success of the NASA satellite COBE, that in 1992 provided the first detection of the…

We describe and implement an exact, flexible, and computationally efficient algorithm for joint component separation and CMB power spectrum estimation, building on a Gibbs sampling framework. Two essential new features are 1) conditional…

天体物理学 · 物理学 2010-11-11 H. K. Eriksen , J. B. Jewell , C. Dickinson , A. J. Banday , K. M. Gorski , C. R. Lawrence

Studies of cosmic microwave background (CMB) are often limited by foreground contamination. Foreground cleaning is performed either in harmonic or pixel space after data cuts have excluded sky areas of strong contamination. We present a…

宇宙学与河外天体物理 · 物理学 2025-09-05 Hayley C. Nofi , Graeme E. Addison , Charles L. Bennett , Laura Herold , J. L. Weiland

The polarization modes of the cosmological microwave background are an invaluable source of information for cosmology, and a unique window to probe the energy scale of inflation. Extracting such information from microwave surveys requires…

宇宙学与河外天体物理 · 物理学 2015-11-04 Jerome Bobin , Florent Sureau , Jean-Luc Starck

We present a technique for the blind separation of components in CMB data. The method uses a spectral EM algorithm which recovers simultaneously component templates, their emission law as a function of wavelength, and noise levels. We test…

天体物理学 · 物理学 2009-11-07 H. Snoussi , G. Patanchon , J. F. Macias-Perez , A. Mohammad-Djafari , J. Delabrouille

One of the main obstacles for extracting the cosmic microwave background (CMB) signal from observations in the mm/sub-mm range is the foreground contamination by emission from Galactic component: mainly synchrotron, free-free, and thermal…

宇宙学与河外天体物理 · 物理学 2015-02-07 H. U. Nørgaard-Nielsen

We investigate the possibility of reconstructing the initial spectrum of density fluctuations from the cosmic microwave background (CMB) anisotropy. As a first step toward this program, we consider a spatially flat, CDM dominated universe.…

天体物理学 · 物理学 2009-10-09 Makoto Matsumiya , Misao Sasaki , Jun'ichi Yokoyama

Accurate measurements of the cosmic microwave background (CMB) anisotropies with an angular resolution of a few arcminutes can be used to determine fundamental cosmological parameters such as the densities of baryons, cold and hot dark…

天体物理学 · 物理学 2016-01-13 J. Richard Bond , George Efstathiou , Max Tegmark

First results of a Cosmic Microwave Background (CMB) anisotropy experiment conducted at the Observatorio del Teide (Tenerife, Spain) are presented. The instrument is a four channel (3.1, 2.1, 1.3 and 1.1 mm) $^3$He bolometer system coupled…

The natural approach to a spectral analysis of data distributed on the sky employs spherical harmonic decomposition. A common problem encountered in practical astronomy is the lack of full sky coverage in the available data. For example,…

天体物理学 · 物理学 2009-10-22 Krzysztof M. Gorski

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…

We present a Bayesian parametric component separation method for polarised microwave sky maps. We solve jointly for the primary cosmic microwave background (CMB) signal and the main Galactic polarised foreground components. For the latter,…

宇宙学与河外天体物理 · 物理学 2022-10-12 Roger de Belsunce , Steven Gratton , George Efstathiou

The presence of astrophysical emissions between the last scattering surface and our vantage point requires us to apply a foreground mask on CMB sky map, leading to large cut around the Galactic equator and numerous holes. Since many CMB…

宇宙学与河外天体物理 · 物理学 2012-04-17 Jaiseung Kim , Pavel Naselsky , Nazzareno Mandolesi

We reconsider the pixel-based, "template" polarized foreground removal method within the context of a next-generation, low-noise, low-resolution (0.5 degree FWHM) space-borne experiment measuring the cosmological B-mode polarization signal…

宇宙学与河外天体物理 · 物理学 2015-05-27 Nobuhiko Katayama , Eiichiro Komatsu

Polarized Galactic foregrounds are one of the primary sources of systematic error in measurements of the B-mode polarization of the Cosmic Microwave Background (CMB). Experiments are becoming increasingly sensitive to complexities in the…

宇宙学与河外天体物理 · 物理学 2018-11-13 Brandon S. Hensley , Philip Bull