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We are presenting an Internal Linear Combination (ILC) CMB map, in which the foreground is reduced through harmonic variance minimization. We have derived our method by converting a general form of pixel-space approach into spherical…

Astrophysics · Physics 2009-09-29 Jaiseung Kim , Pavel Naselsky , Per Rex Christensen

In order to extract cosmological information from observations of the millimeter and submillimeter sky, foreground components must first be removed to produce an estimate of the cosmic microwave background (CMB). We developed a…

Cosmology and Nongalactic Astrophysics · Physics 2020-11-10 Matthew A. Petroff , Graeme E. Addison , Charles L. Bennett , Janet L. Weiland

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…

Astrophysics · Physics 2009-11-07 C. Hernandez-Monteagudo , A. Kashlinsky , F. Atrio-Barandela

It is a recurrent issue in astronomical data analysis that observations are unevenly sampled or incomplete maps with missing patches or intentionaly masked parts. In addition, many astrophysical emissions are non stationary processes over…

Astrophysics · Physics 2016-02-17 Y. Moudden , J. -F. Cardoso , J. -L. Starck , J. Delabrouille

Fast Independent Component Analysis (FastICA) is a component separation algorithm based on the levels of non-Gaussianity. Here we apply the FastICA to the component separation problem of the microwave background including carbon monoxide…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Kiyotomo Ichiki , Ryohei Kaji , Hiroaki Yamamoto , Tsutomu T. Takeuchi , Yasuo Fukui

Galactic foregrounds are the main obstacle to observations of the cosmic microwave background (CMB) $B$-mode polarization. In addition to obscuring the inflationary $B$-mode signal by several orders of magnitude, Galactic foregrounds have…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-17 Mathieu Remazeilles , Aditya Rotti , Jens Chluba

One of the key steps in Cosmic Microwave Background (CMB) data analysis is component separation to recover the CMB signal from multi-frequency observations contaminated by foreground emissions. Needlet Internal Linear Combination (NILC) is…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-26 Debabrata Adak

We present a blind multi-detector multi-component spectral matching method for all sky observations of the cosmic microwave background, working on the spherical harmonics basis. The method allows to estimate on a set of observation maps the…

Astrophysics · Physics 2007-05-23 G. Patanchon , H. Snoussi , J. F. Cardoso , J. Delabrouille

Standard cosmic microwave background (CMB) analyses constrain cosmological and astrophysical parameters by fitting parametric models to multifrequency power spectra (MFPS). However, such methods do not optimally weight maps in power…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-25 Kristen M. Surrao , J. Colin Hill

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,…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-12 Roger de Belsunce , Steven Gratton , George Efstathiou

The presence of astrophysical emissions in microwave observations forces us to perform component separation to extract the Cosmic Microwave Background (CMB) signal. However, even in the most optimistic cases, there are still strongly…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-26 C. Gimeno-Amo , E. Martínez-González , R. B. Barreiro

Observations of cosmic microwave background polarisation, essential for probing a potential phase of inflation in the early universe, suffer from contamination by polarised emission from the Galactic interstellar medium. This work combines…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-25 Jacques Delabrouille

We prepare real-life Cosmic Microwave Background (CMB) lensing extraction with the forthcoming Planck satellite data, by studying two systematic effects related to the foregrounds contamination: the impact of foreground residuals after a…

Cosmology and Nongalactic Astrophysics · Physics 2009-11-12 L. Perotto , J. Bobin , S. Plaszczynski , J. -L. Starck , A. Lavabre

We present new clean maps of the CMB temperature anisotropies (as measured by Planck) constructed with a novel internal linear combination (ILC) algorithm using directional, scale-discretised wavelets --- Scale-discretised, directional…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-24 Keir K. Rogers , Hiranya V. Peiris , Boris Leistedt , Jason D. McEwen , Andrew Pontzen

A functional approximation to implement Bayesian source separation analysis is introduced and applied to separation of the Cosmic Microwave Background (CMB) using WMAP data. The approximation allows for tractable full-sky map…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Simon P. Wilson , Jiwon Yoon

Recovering the Cosmic Microwave Background (CMB) from WMAP data requires galactic foreground emissions to be accurately separated out. Most component separation techniques rely on second order statistics such as Internal Linear Combination…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 J. Bobin , F. Sureau , P. Paykari , A. Rassat , S. Basak , J. -L. Starck

We investigate the extent to which foreground cleaned CMB maps can be used to estimate the cosmological parameters at small scales. We use the SMICA method, a blind separation technique which works directly at the spectral level. In this…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-17 C. Umiltà , J. F. Cardoso , K. Benabed , M. Le Jeune

We present a methodology to recover cosmic microwave background (CMB) polarization in which the quantity $P = Q+ iU$ is linearly combined at different frequencies using complex coefficients. This is the most general linear combination of…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-06 R. Fernández-Cobos , A. Marcos-Caballero , P. Vielva , E. Martínez-González , R. B. Barreiro

The Planck satellite will map the full sky at nine frequencies from 30 to 857 GHz. The CMB intensity and polarization that are its prime targets are contaminated by foreground emission. The goal of this paper is to compare proposed methods…

One of the main obstacles for extracting the Cosmic Microwave Background (CMB) from mm/submm observations is the pollution from the main Galactic components: synchrotron, free-free and thermal dust emission. The feasibility of using simple…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-20 H. U. Nørgaard-Nielsen