Résumé / Abstract Journal-club_Doctorants

Journal-club Doctorants / Journal-club PhD students

« Annoying foregrounds in CMB and what we can do about it »

Caterina Umilta
Institut d'Astrophysique de Paris (Paris, France)

The Planck mission provided whole sky maps in the microwave range, which
have opened a window on precision cosmic microwave background (CMB)
science in cosmology. For this purpose, accuracy in the separation
technique of foreground astrophysical emissions becomes crucial. A lot of
effort has been done within the Planck Collaboration, however, the CMB
maps they delivered still have a residual foreground contamination too
high for cosmological exploitation.
Among these residuals, the unresolved point sources background is one of
the most perturbing, since this is a not well known emission ad since it
is degenerate with the small scales of the CMB angular power spectrum. I
will present our work to tackle this problem, which is based on putting
some prior constraint on the analysis to address the point sources
contamination. This constraint breaks the degeneracy and allows, through
the blind component separation algorithm SMICA, to better characterize the
foreground residual, which is a crucial step towards estimating
cosmological parameters.
mercredi 11 janvier 2017 - 17:00
Salle Entresol Daniel Chalonge, Institut d'Astrophysique
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