1. Planck 2018 results
- Author
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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, Jaiseung, 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., 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 of the Polish Academy of Sciences, California Institute of Technology, University of Toronto, Lawrence Berkeley National Laboratory, Université Pierre and 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, The 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, Aalto-yliopisto, and Aalto University
- Subjects
Turbulence ,Local insterstellar matter ,Magnetic fields ,Polarization ,ISM [Submillimeter] ,Dust ,Astrophysics::Cosmology and Extragalactic Astrophysics ,Extinction ,Astrophysics::Galaxy Astrophysics - 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.
- Published
- 2020