Mapping the CMB with QUBIC spectral imaging

TL;DR

QUBIC is a spectral imaging telescope designed to detect primordial B-modes in the CMB by combining bolometric sensitivity with interferometric systematic understanding, enabling improved foreground separation.

Contribution

Development of three novel map-making methods leveraging QUBIC's spectral imaging capabilities for better component separation in CMB observations.

Findings

QUBIC resumed sky observations in March during commissioning.

Three map-making methods were developed: frequency, component, and neural network.

Spectral imaging improves foreground removal in CMB polarization measurements.

Abstract

QUBIC, the Q & U Bolometric Interferometer for Cosmology, is a telescope that observes the polarisation of the sky in the millimetre-wavelength range. Its goal is to detect the primordial B-modes of polarisation in the cosmic microwave background by combining the sensitivity of bolometers with the good understanding of interferometry systematics. This dual aspect of QUBIC allows it to perform spectral imaging, that is, obtaining spatial and spectral information of the sky simultaneously. This makes the separation of components with complex spectral energy distributions easier, hence improving the performance of foregrounds removal. We developed three different map making methods (frequency, component and neural network map making) that take advantage of these characteristics. Moreover, QUBIC resumed observing the sky early March and is continuing its commisioning phase with, namely, observations of the Moon.