Krachmalnicoff, N.; Matsumura, T.; de la Hoz, E.; Basak, S.; Gruppuso, A.; Minami, Y.; Baccigalupi, C.; Komatsu, E.; Martínez-González, E.; Vielva, P.; Aumont, J.; Aurlien, R.; Azzoni, S.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Bersanelli, M.; Calabrese, E.; Carones, A.; Casas, F. J.; Cheung, K.; Chinone, Y.; Columbro, F.; de Bernardis, P.; Diego-Palazuelos, P.; Errard, J.; Finelli, F.; Fuskeland, U.; Galloway, M.; Genova-Santos, R. T.; Gerbino, M.; Ghigna, T.; Giardiello, S.; Gjerløw, E.; Hazumi, M.; Henrot-Versillé, S.; Kisner, T.; Lamagna, L.; Lattanzi, M.; Levrier, F.; Luzzi, G.; Maino, D.; Masi, S.; Migliaccio, M.; Montier, L.; Morgante, G.; Mot, B.; Nagata, R.; Nati, F.; Natoli, P.; Pagano, L.; Paiella, A.; Paoletti, D.; Patanchon, G.; Piacentini, F.; Polenta, G.; Poletti, D.; Puglisi, G.; Remazeilles, M.; Rubino-Martin, J.; Sasaki, M.; Shiraishi, M.; Signorelli, G.; Stever, S.; Tartari, A.; Tristram, M.; Tsuji, M.; Vacher, L.; Wehus, I. K.; Zannoni, M.; The LiteBIRD collaboration
Journal of Cosmology and Astroparticle Physics
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.
Anisotropy of the Cosmic Microwave Background
The general goal of this project is to determine and characterize the spatial and spectral variations in the temperature and polarisation of the Cosmic Microwave Background in angular scales from several arcminutes to several degrees. The primordial matter density fluctuations which originated the structure in the matter distribution of the present