Pour vous authentifier, privilégiez eduGAIN / To authenticate, prefer eduGAINeu

Jan 17 – 19, 2023
Europe/Paris timezone

Spectral-Imaging with QUBIC : a new window to galactic foregrounds

Jan 18, 2023, 3:00 PM
Amphi Charpak (LPNHE)

Amphi Charpak



Mathias Régnier


M. Regnier1, E. Manzan2,3, S. Paradiso2,3, L. Zapelli2 on behalf of
the QUBIC collaboration
1 Universit ́e de Paris, CNRS, Astroparticule et Cosmologie, F-75006 Paris, France
2 Universit`a degli studi di Milano, Milano, Italy
3 INFN sezione di Milano, 20133 Milano, Italy
The Q&U Bolometric Interferometer for Cosmology (QUBIC) is the first
bolometric interferometer that aims at measuring the primordial B-mode po-
larization of the CMB. A Technological Demonstrator working in the 150 GHz
channel will observe the sky from Alto Chorillo, Argentina, starting from the
end of 2022. Subsequently, the full instrument will be operational and observe
in two frequency bands, centered at 150 GHz and 220 GHz.
Bolometric interferometry is a novel technique that combines the sensitivity
from bolometric detectors with the control of instrumental systematic effects
from interferometry. Furthermore, a unique feature of bolometric interferometry
is spectral imaging: the ability to recover the sky signal in several sub-bands
within the physical band, providing a spectral resolution unattainable for a
traditional imager (∆ν/ν ∼ 0.04).
In this study we investigate how the increased spectral resolution provided
by Bolometric Interferometry can resolve Galactic foreground complexity and
provide robustness to foreground mitigation for primordial B-mode studies. For
this purpose, we addressed the component separation procedure for two different
experimental configurations. The first one consists of the anticipated CMB-
S4 sensitivities and frequency coverage; for the second one, we extended the
CMB-S4 set up with QUBIC spectral resolution (corresponding to a bolometric
interferometry version of the same experiment).
Our results indicates that unaccounted dust frequency decorrelations lead to
a biased result of the order of r ≃ 10−3. However, when changing the spectral
resolution, the bias also changes thus hinting that the estimated r is not due to
primordial CMB B-modes.

Presentation materials