In-flight polarization angle calibration for LiteBIRD: blind challenge and cosmological implications
Creators: name: Krachmalnicoff, Nicoletta
name: Matsumura, Tomotake
name: de la Hoz, Elena
name: Basak, Soumen
name: Gruppuso, Alessandro
name: Minami, Yuto
name: Baccigalupi, Carlo
name: Komatsu, Eiichiro
name: Martínez-González, Enrique
name: Vielva, Patricio
name: Aumont, Jonathan
name: Aurlien, Ragnhild
name: Azzoni, Susanna
name: Banday, Anthony J.
name: Barreiro, Rita B.
name: Bartolo, Nicola
name: Bersanelli, Marco
name: Calabrese, Erminia
name: Carones, Alessandro
name: Casas, Francisco J.
name: Cheung, Kolen
name: Chinone, Yuji
name: Columbro, Fabio
name: de Bernardis, Paolo
name: Diego-Palazuelos, Patricia
name: Errard, Josquin
name: Finelli, Fabio
name: Fuskeland, Unni
name: Galloway, Mathew
name: Genova-Santos, Ricardo T.
name: Gerbino, Martina
name: Ghigna, Tommaso
name: Giardiello, Serena
name: Gjerløw, Eirik
name: Hazumi, Masashi
name: Henrot-Versillé, Sophie
name: Kisner, Theodore
name: Lamagna, Luca
name: Lattanzi, Massimiliano
name: Levrier, François
name: Luzzi, Gemma
name: Maino, Davide
name: Masi, Silvia
name: Migliaccio, Marina
name: Montier, Ludovic
name: Morgante, Gianluca
name: Mot, Baptiste
name: Nagata, Ryo
name: Nati, Federico
name: Natoli, Paolo
name: Pagano, Luca
name: Paiella, Alessandro
name: Paoletti, Daniela
name: Patanchon, Guillaume
name: Piacentini, Francesco
name: Polenta, Gianluca
name: Poletti, Davide
name: Puglisi, G.
name: Remazeilles, Mathieu
name: Rubino-Martin, Jose Alberto
name: Sasaki, Manami
name: Shiraishi, Maresuke
name: Signorelli, Giovanni
name: Stever, Samantha
name: Tartari, Andrea
name: Tristram, Matthieu
name: Tsuji, Masatoshi
name: Vacher, Léo
name: Wehus, Ingunn K.
name: Zannoni, Mario
Publisher: name: arXiv
Year: 2021
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: We present a demonstration of the in-flight polarization angle calibration for the JAXA/ISAS second strategic large class mission, LiteBIRD, and estimate its impact on the measurement of the tensor-to-scalar ratio parameter, r, using simulated data. We generate a set of simulated sky maps with CMB and polarized foreground emission, and inject instrumental noise and polarization angle offsets to the 22 (partially overlapping) LiteBIRD frequency channels. Our in-flight angle calibration relies on nulling the EB cross correlation of the polarized signal in each channel. This calibration step has been carried out by two independent groups with a blind analysis, allowing an accuracy of the order of a few arc-minutes to be reached on the estimate of the angle offsets. Both the corrected and uncorrected multi-frequency maps are propagated through the foreground cleaning step, with the goal of computing clean CMB maps. We employ two component separation algorithms, the Bayesian-Separation of Components and Residuals Estimate Tool (B-SeCRET), and the Needlet Internal Linear Combination (NILC). We find that the recovered CMB maps obtained with algorithms that do not make any assumptions about the foreground properties, such as NILC, are only mildly affected by the angle miscalibration. However, polarization angle offsets strongly bias results obtained with the parametric fitting method. Once the miscalibration angles are corrected by EB nulling prior to the component separation, both component separation algorithms result in an unbiased estimation of the r parameter. While this work is motivated by the conceptual design study for LiteBIRD, its framework can be broadly applied to any CMB polarization experiment. In particular, the combination of simulation plus blind analysis provides a robust forecast by taking into account not only detector sensitivity but also systematic effects.
description: Submitted to JCAP