Making maps of Cosmic Microwave Background polarization for B-mode studies: the POLARBEAR example
Creators: name: Poletti, Davide
name: Fabbian, Giulio
name: Jeune, Maude Le
name: Peloton, Julien
name: Arnold, Kam
name: Baccigalupi, Carlo
name: Barron, Darcy
name: Beckman, Shawn
name: Borrill, Julian
name: Chapman, Scott
name: Chinone, Yuji
name: Cukierman, Ari
name: Ducout, Anne
name: Elleflot, Tucker
name: Errard, Josquin
name: Feeney, Stephen
name: Goeckner-Wald, Neil
name: Groh, John
name: Hall, Grantland
name: Hasegawa, Masaya
name: Hazumi, Masashi
name: Hill, Charles
name: Howe, Logan
name: Inoue, Yuki
name: Jaffe, Andrew H.
name: Jeong, Oliver
name: Katayama, Nobuhiko
name: Keating, Brian
name: Keskitalo, Reijo
name: Kisner, Theodore
name: Kusaka, Akito
name: Lee, Adrian T.
name: Leon, David
name: Linder, Eric
name: Lowry, Lindsay
name: Matsuda, Frederick
name: Navaroli, Martin
name: Paar, Hans
name: Puglisi, Giuseppe
name: Reichardt, Christian L.
name: Ross, Colin
name: Siritanasak, Praween
name: Stebor, Nathan
name: Steinbach, Bryan
name: Stompor, Radek
name: Suzuki, Aritoki
name: Tajima, Osamu
name: Teply, Grant
name: Whitehorn, Nathan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences
subject: FOS: Physical sciences

description: Analysis of cosmic microwave background (CMB) datasets typically requires some filtering of the raw time-ordered data. Filtering is frequently used to minimize the impact of low frequency noise, atmospheric contributions and/or scan synchronous signals on the resulting maps. In this work we explicitly construct a general filtering operator, which can unambiguously remove any set of unwanted modes in the data, and then amend the map-making procedure in order to incorporate and correct for it. We show that such an approach is mathematically equivalent to the solution of a problem in which the sky signal and unwanted modes are estimated simultaneously and the latter are marginalized over. We investigate the conditions under which this amended map-making procedure can render an unbiased estimate of the sky signal in realistic circumstances. We then study the effects of time-domain filtering on the noise correlation structure in the map domain, as well as impact it may have on the performance of the popular pseudo-spectrum estimators. We conclude that although maps produced by the proposed estimators arguably provide the most faithful representation of the sky possible given the data, they may not straightforwardly lead to the best constraints on the power spectra of the underlying sky signal and special care may need to be taken to ensure this is the case. By contrast, simplified map-makers which do not explicitly correct for time-domain filtering, but leave it to subsequent steps in the data analysis, may perform equally well and be easier and faster to implement. We focus on polarization-sensitive measurements targeting the B-mode component of the CMB signal and apply the proposed methods to realistic simulations based on characteristics of an actual CMB polarization experiment, POLARBEAR.
description: 26 pages