QUBIC II: Spectro-Polarimetry with Bolometric Interferometry

MOUSSET, L.; SCÓCCOLA, CLAUDIA G.; AND THE QUBIC COLLABORATION

JOURNAL OF COSMOLOGY AND ASTROPARTICLE PHYSICS

IOP PUBLISHING LTD

Lugar: Londres; Año: 2021

1475-7516

Bolometric interferometry is a novel technique that has the ability toperform spectral imaging. A bolometric interferometer observes the sky in awide frequency band and can reconstruct sky maps in several sub-bands withinthe physical band in post-processing of the data. This provides a powerfulspectral method to discriminate between the cosmic microwave background (CMB)and astrophysical foregrounds. In this paper, the methodology is illustratedwith examples based on the Q & U Bolometric Interferometer for Cosmology(QUBIC) which is a ground-based instrument designed to measure the B-modepolarization of the sky at millimeter wavelengths. We consider the specificcases of point source reconstruction and Galactic dust mapping and wecharacterize the point spread function as a function of frequency. We study thenoise properties of spectral imaging, especially the correlations betweensub-bands, using end-to-end simulations together with a fast noise simulator.We conclude showing that spectral imaging performance are nearly optimal up tofive sub-bands in the case of QUBIC.