XIIIth School of Cosmology
November 12 - 18, 2017IESC, Cargèse
The CMB from A to Z
promises and challenges of the CMB as a cosmological probe

Extracting the Cosmic Microwave Background from multi-frequency observations

Jean-François CARDOSO
Institut d'Astrophysique de Paris


  1. Cosmic background and astrophysical foregrounds
  2. Spherical signal representations: pixels, harmonic modes, wavelets
  3. Optimal filtering,  template fitting, the ILC and its many guises
  4. Blind methods for CMB extraction
  5. The parametric Bayesian approach


The scientific exploitation of CMB data hinges on our ability to extract the CMB signal from the observations delivered by our instruments.  Indeed, the cosmological background is contaminated by the emission of several astrophysical foregrounds (Galactic dust, synchrotron, CIB, radio point sources, etc...).  These lectures review the various ideas and methods which have been implemented in the Planck collaboration for separating the signal components, focusing on CMB extraction and emphasizing the statistical aspects of this critical task.


  • Articles
    • "Component separation methods for the Planck mission", Astronomy and Astrophysics, 2008, http://arxiv.org/abs/0805.0269
    • "Planck 2013 results. XII. Component separation", Astronomy and Astrophysics, http://arxiv.org/abs/1303.5072
    • "Planck 2015 results. IX. Diffuse component separation: CMB maps", Astronomy and Astrophysics, 10.1051/0004-6361/201525936, arXiv:1502.05956