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Related papers: Optimized Large-Scale CMB Likelihood And Quadratic…

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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…

Astrophysics · Physics 2009-11-07 E. Martinez-Gonzalez , J. M. Diego , P. Vielva , J. Silk

We estimate CMB polarization and temperature power spectra using WMAP 5-year foreground contaminated maps. The power spectrum is estimated by using a model independent method, which does not utilize directly the diffuse foreground templates…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 Pramoda Kumar Samal , Rajib Saha , Jacques Delabrouille , Simon Prunet , Pankaj Jain , Tarun Souradeep

A maximum-likelihood method is presented for estimating the power spectrum of anisotropies in the cosmic microwave background (CMB) from interferometer observations. The method calculates flat band-power estimates in separate bins in…

Astrophysics · Physics 2009-11-07 M. P. Hobson , Klaus Maisinger

As the Cosmic Microwave Background (CMB) radiation is observed to higher and higher angular resolution the size of the resulting datasets becomes a serious constraint on their analysis. In particular current algorithms to determine the…

Astrophysics · Physics 2007-05-23 Julian Borrill

We present a CMB large-scale polarization dataset obtained by combining WMAP Ka, Q and V with Planck 70 GHz maps. We employ the legacy frequency maps released by the WMAP and Planck collaborations and perform our own Galactic foreground…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-04 U. Natale , L. Pagano , M. Lattanzi , M. Migliaccio , L. P. Colombo , A. Gruppuso , P. Natoli , G. Polenta

The statistical properties of a map of the primary fluctuations in the cosmic microwave background (CMB) may be specified to high accuracy by a few thousand power spectra measurements, provided the fluctuations are gaussian, yet the number…

Astrophysics · Physics 2009-11-07 Sujata Gupta , Alan F. Heavens

In the context of cosmic microwave background (CMB) data analysis, we compare the efficiency at large scale of two angular power spectrum algorithms, implementing, respectively, the quadratic maximum likelihood (QML) estimator and the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Diego Molinari , Alessandro Gruppuso , Gianluca Polenta , Carlo Burigana , Adriano De Rosa , Paolo Natoli , Fabio Finelli , Francesco Paci

We investigate sets of random variables that can be arranged sequentially such that a given variable only depends conditionally on its immediate predecessor. For such sets, we show that the full joint probability distribution may be…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 E. Gjerløw , K. Mikkelsen , H. K. Eriksen , K. M. Górski , G. Huey , J. B. Jewell , S. K. Næss , G. Rocha , D. S. Seljebotn , I. K. Wehus

The existing analysis of WMAP data is based on approximations for the likelihood function, which is likely to be inaccurate on large scales. Here we present exact evaluations of the likelihood of the low multipoles by direct inversion of…

Astrophysics · Physics 2009-11-10 A. Slosar , U. Seljak , A. Makarov

We describe a sampling method to estimate the polarized CMB signal from observed maps of the sky. We use a Metropolis-within-Gibbs algorithm to estimate the polarized CMB map, containing Q and U Stokes parameters at each pixel, and its…

We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-06 Duncan Hanson , Antony Lewis

Strong foreground contamination in high resolution CMB data requires masking which introduces statistical anisotropies and renders a full maximum likelihood analysis numerically intractable. Standard analysis methods like the pseudo-C_l…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-26 H. F. Gruetjen , E. P. S. Shellard

We develop the XFaster Cosmic Microwave Background (CMB) temperature and polarization anisotropy power spectrum and likelihood technique for the Planck CMB satellite mission. We give an overview of this estimator and its current…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 G. Rocha , C. R. Contaldi , J. R. Bond , K. M. Gorski

Quadratic methods with heuristic weighting (e.g. pseudo-C_l or correlation function methods) represent an efficient way to estimate power spectra of the cosmic microwave background (CMB) anisotropies and their polarization. We construct the…

Astrophysics · Physics 2008-11-26 Anthony Challinor , Gayoung Chon

We extend the analysis of Gabor transforms on a Cosmic Microwave Background (CMB) temperature map (Hansen, Gorski and Hivon 2002) to polarisation. We study the temperature and polarisation power spectra on the cut sky, the so-called pseudo…

Astrophysics · Physics 2008-11-26 Frode K. Hansen , Krzysztof M. Gorski

Most parameter constraints obtained from cosmic microwave background (CMB) anisotropy data are based on power estimates and rely on approximate likelihood functions; computational difficulties generally preclude an exact analysis based on…

Astrophysics · Physics 2009-11-06 M. Douspis , J. G. Bartlett , A. Blanchard , M. Le Dour

Estimation of the angular power spectrum of the Cosmic Microwave Background (CMB) on a small patch of sky is usually plagued by serious spectral leakage, specially when the map has a hard edge. Even on a full sky map, point source masks can…

Astrophysics · Physics 2009-11-06 Sudeep Das , Amir Hajian , David N. Spergel

Deep surveys of the CMB polarization have more information on the lensing signal than the quadratic estimators (QE) can capture. We showed in a recent work that a CMB lensing power spectrum built from a single optimized CMB lensing mass…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-15 Louis Legrand , Julien Carron

[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…

Astrophysics · Physics 2008-11-26 Chan-Gyung Park , Changbom Park , J. Richard Gott

We discuss the problems of applying Maximum Likelihood methods to the CMB and how one can make it both efficient and optimal. The solution is a generalised eigenvalue problem that allows virtually no loss of information about the parameter…

Astrophysics · Physics 2007-05-23 Andy Taylor , Alan Heavens , Bill Ballinger , Max Tegmark