Planck 2018 results

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Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Date
2020-09-01
Department
Université Paris-Sud
École normale supérieure
IRAP
University of Cambridge
Université Paul Sabatier
International School for Advanced Studies
University of the Western Cape
Universidad de Cantabria
University of Padova
Indian Institute of Science Education and Research Thiruvananthapuram
Institut d 'Astrophysique de Paris
University of Milano
Nicolaus Copernicus Astronomical Center
California Institute of Technology
University of Toronto
Lawrence Berkeley National Laboratory
Université Pierre et Marie Curie
University of Ferrara
Cardiff University
University of Sussex
University of KwaZulu-Natal
Institut national de physique nucléaire et de physique des particules
National Research Council of Italy
Sapienza University of Rome
INAF - Osservatorio Astronomico di Padova
Université de Bretagne Occidentale
University of Manchester
University of Tokyo
European Space Astronomy Centre
Max-Planck-Institut für Astrophysik
University of Oslo
UMR7095
African Institute for Mathematical Sciences
Osservatorio Astronomico di Trieste
Princeton University
Simon Fraser University
University of Chicago
University of La Laguna
Stockholm University
Cahill Center for Astronomy and Astrophysics
University of Oviedo
Jet Propulsion Laboratory
Stanford University
Sun Yat-Sen University
Imperial College London
University of Helsinki
CNRS
University of California Santa Barbara
National Institute for Nuclear Physics
University College London
University of Rome Tor Vergata
Université Paris-Saclay
University of Nottingham
Agenzia Spaziale Italiana
Radboud University Nijmegen
Department of Applied Physics
University of British Columbia
European Space Research and Technology Centre
Università Degli Studi di Trieste
Istituto di Astrofisica Spaziale e Fisica Cosmica di Bologna
University of Illinois at Urbana-Champaign
University of California San Diego
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Language
en
Pages
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Astronomy and Astrophysics, Volume 641
Abstract
Observations of the submillimetre emission from Galactic dust, in both total intensity I and polarization, have received tremendous interest thanks to the Planck full-sky maps. In this paper we make use of such full-sky maps of dust polarized emission produced from the third public release of Planck data. As the basis for expanding on astrophysical studies of the polarized thermal emission from Galactic dust, we present full-sky maps of the dust polarization fraction p, polarization angle ψ, and dispersion function of polarization angles «. The joint distribution (one-point statistics) of p and NH confirms that the mean and maximum polarization fractions decrease with increasing NH. The uncertainty on the maximum observed polarization fraction, pmax = 22.0-1.4+3.5% at 353 GHz and 80′ resolution, is dominated by the uncertainty on the Galactic emission zero level in total intensity, in particular towards diffuse lines of sight at high Galactic latitudes. Furthermore, the inverse behaviour between p and « foundearlier is seen to be present at high latitudes. This follows the «p-1 relationship expected from models of the polarized sky (including numerical simulations of magnetohydrodynamical turbulence) that include effects from only the topology of the turbulent magnetic field, but otherwise have uniform alignment and dust properties. Thus, the statistical properties of p, ψ, and « for the most part reflect the structure of the Galactic magnetic field. Nevertheless, we search for potential signatures of varying grain alignment and dust properties. First, we analyse the product map « × p, looking for residual trends. While the polarization fraction p decreases by a factor of 3-4 between NH = 1020 cm-2 and NH = 2 × 1022 cm-2, out of the Galactic plane, this product « × p only decreases by about 25%. Because « is independent of the grain alignment efficiency, this demonstrates that the systematic decrease in p with NH is determined mostly by the magnetic-field structure and not by a drop in grain alignment. This systematic trend is observed both in the diffuse interstellar medium (ISM) and in molecular clouds of the Gould Belt. Second, we look for a dependence of polarization properties on the dust temperature, as we would expect from the radiative alignment torque (RAT) theory. We find no systematic trend of « × p with the dust temperature Td, whether in the diffuse ISM or in the molecular clouds of the Gould Belt. In the diffuse ISM, lines of sight with high polarization fraction p and low polarization angle dispersion « tend, on the contrary, to have colder dust than lines of sight with low p and high «. We also compare the Planck thermal dust polarization with starlight polarization data in the visible at high Galactic latitudes. The agreement in polarization angles is remarkable, and is consistent with what we expect from the noise and the observed dispersion of polarization angles in the visible on the scale of the Planck beam. The two polarization emission-to-extinction ratios, RP/p and RS/V, which primarily characterize dust optical properties, have only a weak dependence on the column density, and converge towards the values previously determined for translucent lines of sight. We also determine an upper limit for the polarization fraction in extinction, pV/E(B - V), of 13% at high Galactic latitude, compatible with the polarization fraction p ≈ 20% observed at 353 GHz. Taken together, these results provide strong constraints for models of Galactic dust in diffuse gas.
Description
Keywords
Dust, Extinction, Local insterstellar matter, Magnetic fields, Polarization, Submillimeter: ISM, Turbulence
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Citation
Aghanim , N , Akrami , Y , Alves , M I R , Ashdown , M , Aumont , J , Baccigalupi , C , Ballardini , M , Banday , A J , Barreiro , R B , Bartolo , N , Basak , S , Benabed , K , Bernard , J P , Bersanelli , M , Bielewicz , P , Bock , J J , Bond , J R , Borrill , J , Bouchet , F R , Boulanger , F , Bracco , A , Bucher , M , Burigana , C , Calabrese , E , Cardoso , J F , Carron , J , Chary , R R , Chiang , H C , Colombo , L P L , Combet , C , Crill , B P , Cuttaia , F , De Bernardis , P , De Zotti , G , Delabrouille , J , Delouis , J M , Di Valentino , E , Dickinson , C , Diego , J M , Doré , O , Douspis , M , Ducout , A , Dupac , X , Efstathiou , G , Elsner , F , Enßlin , T A , Eriksen , H K , Falgarone , E , Fantaye , Y , Fernandez-Cobos , R , Ferrière , K , Finelli , F , Forastieri , F , Frailis , M , Fraisse , A A , Franceschi , E , Frolov , A , Galeotta , S , Galli , S , Ganga , K , Génova-Santos , R T , Gerbino , M , Ghosh , T , González-Nuevo , J , Górski , K M , Gratton , S , Green , G , Gruppuso , A , Gudmundsson , J E , Guillet , V , Handley , W , Hansen , F K , Helou , G , Herranz , D , Hivon , E , Huang , Z , Jaffe , A H , Jones , W C , Keihänen , E , Keskitalo , R , Kiiveri , K , Kim , J , Krachmalnicoff , N , Kunz , M , Kurki-Suonio , H , Lagache , G , Lamarre , J M , Lasenby , A , Lattanzi , M , Lawrence , C R , Le Jeune , M , Levrier , F , Liguori , M , Lilje , P B , Lindholm , V , López-Caniego , M , Lubin , P M , Ma , Y Z , Maciás-Pérez , J F , Maggio , G , Maino , D , Mandolesi , N , Mangilli , A , Marcos-Caballero , A , Maris , M , Martin , P G , Martínez-González , E , Matarrese , S , Mauri , N , McEwen , J D , Melchiorri , A , Mennella , A , Migliaccio , M , Miville-Deschênes , M A , Molinari , D , Moneti , A , Montier , L , Morgante , G , Moss , A , Natoli , P , Pagano , L , Paoletti , D , Patanchon , G , Perrotta , F , Pettorino , V , Piacentini , F , Polastri , L , Polenta , G , Puget , J L , Rachen , J P , Reinecke , M , Remazeilles , M , Renzi , A , Ristorcelli , I , Rocha , G , Rosset , C, Roudier , G , Rubiño-Martín , J A , Ruiz-Granados , B , Salvati , L , Sandri , M , Savelainen , M , Scott , D , Sirignano , C , Sunyaev , R , Suur-Uski , A S , Tauber , J A , Tavagnacco , D , Tenti , M , Toffolatti , L , Tomasi , M , Trombetti , T , Valiviita , J , Vansyngel , F , Van Tent , B , Vielva , P , Villa , F , Vittorio , N , Wandelt , B D , Wehus , I K , Zacchei , A & Zonca , A 2020 , ' Planck 2018 results : XII. Galactic astrophysics using polarized dust emission ' , Astronomy and Astrophysics , vol. 641 , 12 . https://doi.org/10.1051/0004-6361/201833885