Component separation methods for the PLANCK mission

By Samuel Leach, Jean-François Cardoso, C. Baccigalupi, Rita Belén Barreiro, Marc Betoule, Jérôme Bobin, A. Bonaldi, Jacques Delabrouille, G. Zotti, C. Dickinson and 20 more. 2008

212 citations recorded by the source corpus.

Context. 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. Aims. The goal of this paper is to compare proposed methods for separating CMB from foregrounds based on their different spectral and spatial characteristics, and to separate the foregrounds into “components” with different physical origins (Galactic synchrotron, free-free and dust emissions; extra-galactic and far-IR point sources; Sunyaev-Zeldovich effect, etc.) Methods. A component separation challenge has been organised, based on a set of realistically complex simulations of sky emission. Several methods including those based on internal template subtraction, maximum entropy method, parametric method, spatial and harmonic cross correlation methods, and independent component analysis have been tested. Results. Different methods proved to be effective in cleaning the CMB maps of foreground contamination, in reconstructing maps of diffuse Galactic emissions, and in detecting point sources and thermal Sunyaev-Zeldovich signals. The power spectrum of the residuals is, on the largest scales, four orders of magnitude lower than the input Galaxy power spectrum at the foreground minimum. The CMB power spectrum was accurately recovered up to the sixth acoustic peak. The point source detection limit reaches 100 mJy, and about 2300 clusters are detected via the thermal SZ effect on two thirds of the sky. We have found that no single method performs best for all scientific objectives. Conclusions. We foresee that the final component separation pipeline for PLANCK will involve a combination of methods and iterations between processing steps targeted at different objectives such as diffuse component separation, spectral estimation, and compact source extraction.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/08afbccf2d20a6cec85c1b423fa08a8397feb06d

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

The pre-launch Planck Sky Model: a model of sky emission at submillimetre to centimetre wavelengths (2012, methodology): “…developed by several authors have been making use of simulated sky maps to assess the performance of the proposed approaches, or to validate them before application to real data sets (see Leach et al. 2008; Delabrouille & Cardoso 2009; Dunkley et al. 2009, and references therein, for an overview).”
Planck2013 results. XXVIII. ThePlanckCatalogue of Compact Sources (2013, methodology): “Besides, it has previously been used to detect compact sources in astronomical images, including realistic simulations of Planck (López-Caniego et al. 2006; González-Nuevo et al. 2006; Leach et al. 2008) and data from WMAP (López-Caniego et al. 2007; Massardi et al. 2009).”
A refined model for spinning dust radiation (2008, background): “However, foreground separation and removal remains a major challenge for any CMB measurement (e.g. Eriksen et al. 2008; Leach et al. 2008).”
Planck intermediate results. LVII. Joint Planck LFI and HFI data processing (2020, methodology): “SEVEM (Leach et al. 2008; Fernández-Cobos et al. 2012) is based on internal template cleaning in real space.”
Planck Pre-Launch Status: The Planck Mission (2010, background): “Estimates of confusion levels can be extracted from Leach et al. (2008).”
CMB and SZ effect separation with constrained Internal Linear Combinations (2010, methodology): “Some details about PSM simulations can be found in Leach et al. (2008) and Betoule et al. (2009).”
SIMULATIONS OF THE MICROWAVE SKY (2009, methodology): “…et al. 2002; da Silva et al. 2004; Diaferio et al. 2005; Motl et al. 2005; Nagai 2006; Hallman et al. 2007; Pfrommer et al. 2007; Roncarelli et al. 2007; Malte Schäfer & Bartelmann 2007; Leach et al. 2008; Pace et al. 2008; Shaw et al. 2008; Wik et al. 2008; Carbone et al. 2009; Peel et al. 2009).”
Primordial Non-Gaussianity and Bispectrum Measurements in the Cosmic Microwave Background and Large-Scale Structure (2010, background): “Among these, diffuse astrophysical foreground emission (see e.g. Bennett et al., 2003; Leach et al., 2008, and references therein), unresolved point sources (e.g. Komatsu et al., 2003) and secondary anisotropies are probably the most 40 important NG sources.”