Planck intermediate results

XXX. The angular power spectrum of polarized dust emission at intermediate and high Galactic latitudes

¹ APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/lrfu, Observatoire de Paris, Sorbonne Paris Cité, 10 rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France
² African Institute for Mathematical Sciences, 6–8 Melrose Road, Muizenberg, Cape Town, South Africa
³ Agenzia Spaziale Italiana Science Data Center, via del Politecnico snc, 00133 Roma, Italy
⁴ Agenzia Spaziale Italiana, viale Liegi 26, Roma, Italy
⁵ Aix Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille) UMR 7326, 13388 Marseille, France
⁶ Astrophysics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
⁷ Astrophysics & Cosmology Research Unit, School of Mathematics, Statistics & Computer Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, 4000 Durban, South Africa
⁸ Atacama Large Millimeter/submillimeter Array, ALMA Santiago Central Offices, Alonso de Cordova 3107, Vitacura, Casilla 763 0355 Santiago, Chile
⁹ CITA, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8, Canada
¹⁰ CNRS, IRAP, , 9 Av. colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
¹¹ CRANN, Trinity College, Dublin, Ireland
¹² California Institute of Technology, Pasadena, California, USA
¹³ Centre for Theoretical Cosmology, DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA, UK
¹⁴ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan, 1, planta 2, 44001 Teruel, Spain
¹⁵ Computational Cosmology Center, Lawrence Berkeley National Laboratory, Berkeley, California, USA
¹⁶ Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
¹⁷ DSM/Irfu/SPP, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
¹⁸ DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark
¹⁹ Département de Physique Théorique, Université de Genève, 24 Quai E. Ansermet, 1211 Genève 4, Switzerland
²⁰ Departamento de Física, Universidad de Oviedo, Avda. Calvo Sotelo s/n, Oviedo, Spain
²¹ Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, Ontario, Canada
²² Department of Astrophysics/IMAPP, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen, The Netherlands
²³ Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, Canada
²⁴ Department of Physics and Astronomy, Dana and David Dornsife College of Letter, Arts and Sciences, University of Southern California, Los Angeles, CA 90089, USA
²⁵ Department of Physics and Astronomy, University College London, London WC1E 6BT, UK
²⁶ Department of Physics, Florida State University, Keen Physics Building, 77 Chieftan Way, Tallahassee, Florida, USA
²⁷ Department of Physics, Gustaf Hällströmin katu 2a, University of Helsinki, Helsinki, Finland
²⁸ Department of Physics, Princeton University, Princeton, New Jersey, USA
²⁹ Department of Physics, University of California, Berkeley, California, USA
³⁰ Department of Physics, University of California, One Shields Avenue, Davis, California, USA
³¹ Department of Physics, University of California, Santa Barbara, California, USA
³² Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois, USA
³³ Dipartimento di Fisica e Astronomia G. Galilei, Università degli Studi di Padova, via Marzolo 8, 35131 Padova, Italy
³⁴ Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, via Saragat 1, 44122 Ferrara, Italy
³⁵ Dipartimento di Fisica, Università La Sapienza, P.le A. Moro 2, Roma, Italy
³⁶ Dipartimento di Fisica, Università degli Studi di Milano, via Celoria, 16 Milano, Italy
³⁷ Dipartimento di Fisica, Università degli Studi di Trieste, via A. Valerio 2, Trieste, Italy
³⁸ Dipartimento di Fisica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
³⁹ Dipartimento di Matematica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
⁴⁰ Discovery Center, Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
⁴¹ Dpto. Astrofísica, Universidad de La Laguna (ULL), 38206, La Laguna, Tenerife, Spain
⁴² European Southern Observatory, ESO Vitacura, Alonso de Cordova 3107, Vitacura, Casilla 19001 Santiago, Chile
⁴³ European Space Agency, ESAC, Planck Science Office, Camino bajo del Castillo, s/n, Urbanización Villafranca del Castillo, Villanueva de la Cañada, Madrid, Spain
⁴⁴ European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
⁴⁵ Facoltà di Ingegneria, Università degli Studi e-Campus, via Isimbardi 10, 22060 Novedrate ( CO), Italy
⁴⁶ Gran Sasso Science Institute, INFN,viale F. Crispi 7, 67100 L’Aquila, Italy
⁴⁷ HGSFP and University of Heidelberg, Theoretical Physics Department, Philosophenweg 16, 69120 Heidelberg, Germany
⁴⁸ Haverford College Astronomy Department, 370 Lancaster Avenue, Haverford, Pennsylvania, USA
⁴⁹ Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki, Helsinki, Finland
⁵⁰ INAF–Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova, Italy
⁵¹ INAF–Osservatorio Astronomico di Roma, via di Frascati 33, Monte Porzio Catone, Italy
⁵² INAF–Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, Trieste, Italy
⁵³ INAF/IASF Bologna, via Gobetti 101, Bologna, Italy
⁵⁴ INAF/IASF Milano, via E. Bassini 15, Milano, Italy
⁵⁵ INFN, Sezione di Bologna, via Irnerio 46, 40126 Bologna, Italy
⁵⁶ INFN, Sezione di Roma 1, Università di Roma Sapienza, Piazzale Aldo Moro 2, 00185 Roma, Italy
⁵⁷ INFN, Sezione di Roma 2, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
⁵⁸ INFN/National Institute for Nuclear Physics, via Valerio 2, 34127 Trieste, Italy
⁵⁹ IPAG: Institut de Planétologie et d’Astrophysique de Grenoble, Université Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France
⁶⁰ IUCAA, Post Bag 4, Ganeshkhind, Pune University Campus, 411 007 Pune, India
⁶¹ Imperial College London, Astrophysics group, Blackett Laboratory, Prince Consort Road, London, SW7 2AZ, UK
⁶² Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA
⁶³ Institut Universitaire de France, 103 Bd Saint-Michel, 75005 Paris, France
⁶⁴ Institut d’Astrophysique Spatiale, CNRS (UMR 8617) Université Paris-Sud 11, Bâtiment 121, Orsay, France
⁶⁵ Institut d’Astrophysique de Paris, CNRS (UMR 7095), 98bis Boulevard Arago, 75014 Paris, France
⁶⁶ Institute for Space Sciences, Bucharest-Magurale, Romania
⁶⁷ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁶⁸ Institute of Theoretical Astrophysics, University of Oslo, Blindern, Oslo, Norway
⁶⁹ Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, La Laguna, Tenerife, Spain
⁷⁰ Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), Avda. de los Castros s/n, Santander, Spain
⁷¹ Istituto Nazionale di Fisica Nucleare, Sezione di Padova, via Marzolo 8, 35131 Padova, Italy
⁷² Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, USA
⁷³ Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
⁷⁴ Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
⁷⁵ LAL, Université Paris-Sud, CNRS/IN2P3, Orsay, France
⁷⁶ LAPTh, Univ. de Savoie, CNRS, BP110, 74941 Annecy-le-Vieux, France
⁷⁷ LERMA, CNRS, Observatoire de Paris, 61 Avenue de l’Observatoire, Paris, France
⁷⁸ Laboratoire AIM, IRFU/Service d’Astrophysique – CEA/DSM – CNRS – Université Paris Diderot, Bât. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
⁷⁹ Laboratoire Traitement et Communication de l’Information, CNRS (UMR 5141) and Télécom ParisTech, 46 rue Barrault, 75634 Paris Cedex 13, France
⁸⁰ Laboratoire de Physique Subatomique et de Cosmologie, Université Joseph Fourier Grenoble I, CNRS/IN2P3, Institut National Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble Cedex, France
⁸¹ Laboratoire de Physique Théorique, Université Paris-Sud 11 & CNRS, Bâtiment 210, 91405 Orsay, France
⁸² Lawrence Berkeley National Laboratory, Berkeley, California, USA
⁸³ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
⁸⁴ McGill Physics, Ernest Rutherford Physics Building, McGill University, 3600 rue University, Montréal, QC, H3A 2T8, Canada
⁸⁵ National University of Ireland, Department of Experimental Physics, Maynooth, Co. Kildare, Ireland
⁸⁶ Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
⁸⁷ Observational Cosmology, Mail Stop 367-17, California Institute of Technology, Pasadena, CA, 91125, USA
⁸⁸ Optical Science Laboratory, University College London, Gower Street, London, UK
⁸⁹ SB-ITP-LPPC, EPFL, 1015 Lausanne, Switzerland
⁹⁰ SISSA, Astrophysics Sector, via Bonomea 265, 34136 Trieste, Italy
⁹¹ School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, CF24 3AA, UK
⁹² School of Physics and Astronomy, University of Nottingham, Nottingham NG7 2RD, UK
⁹³ Space Research Institute (IKI), Russian Academy of Sciences, Profsoyuznaya Str, 84/32, 117997 Moscow, Russia
⁹⁴ Space Sciences Laboratory, University of California, Berkeley, California, USA
⁹⁵ Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Zelenchukskiy region, 369167 Karachai-Cherkessian Republic, Russia
⁹⁶ Sub-Department of Astrophysics, University of Oxford, Keble Road, Oxford OX1 3RH, UK
⁹⁷ Theory Division, PH-TH, CERN, 1211, Geneva 23, Switzerland
⁹⁸ UPMC Univ. Paris 6, UMR7095, 98bis Boulevard Arago, 75014 Paris, France
⁹⁹ Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse Cedex 4, France
¹⁰⁰ Universities Space Research Association, Stratospheric Observatory for Infrared Astronomy, MS 232-11, Moffett Field, CA 94035, USA
¹⁰¹ University Observatory, Ludwig Maximilian University of Munich, Scheinerstrasse 1, 81679 Munich, Germany
¹⁰² University of Granada, Departamento de Física Teórica y del Cosmos, Facultad de Ciencias, Granada, Spain
¹⁰³ University of Granada, Instituto Carlos I de Física Teórica y Computacional, Granada, Spain
¹⁰⁴ Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland

Received: 19 September 2014
Accepted: 1 December 2014

Abstract

The polarized thermal emission from diffuse Galactic dust is the main foreground present in measurements of the polarization of the cosmic microwave background (CMB) at frequencies above 100 GHz. In this paper we exploit the uniqueness of the Planck HFI polarization data from 100 to 353 GHz to measure the polarized dust angular power spectra C_ℓ^EE and C_ℓ^BB over the multipole range 40 <ℓ< 600 well away from the Galactic plane. These measurements will bring new insights into interstellar dust physics and allow a precise determination of the level of contamination for CMB polarization experiments. Despite the non-Gaussian and anisotropic nature of Galactic dust, we show that general statistical properties of the emission can be characterized accurately over large fractions of the sky using angular power spectra. The polarization power spectra of the dust are well described by power laws in multipole, C_ℓ ∝ ℓ^α, with exponents α^EE,BB = −2.42 ± 0.02. The amplitudes of the polarization power spectra vary with the average brightness in a way similar to the intensity power spectra. The frequency dependence of the dust polarization spectra is consistent with modified blackbody emission with β_d = 1.59 and T_d = 19.6 K down to the lowest Planck HFI frequencies. We find a systematic difference between the amplitudes of the Galactic B- and E-modes, C_ℓ^BB/C_ℓ^EE = 0.5. We verify that these general properties are preserved towards high Galactic latitudes with low dust column densities. We show that even in the faintest dust-emitting regions there are no “clean” windows in the sky where primordial CMB B-mode polarization measurements could be made without subtraction of foreground emission. Finally, we investigate the level of dust polarization in the specific field recently targeted by the BICEP2 experiment. Extrapolation of the Planck 353 GHz data to 150 GHz gives a dust power 𝒟_ℓ^BB ≡ ℓ(ℓ+1)C_ℓ^BB/(2π) of 1.32 × 10^-2 μK_CMB² over the multipole range of the primordial recombination bump (40 <ℓ< 120); the statistical uncertainty is ± 0.29 × 10^-2 μK_CMB² and there is an additional uncertainty (+0.28, −0.24) × 10^-2 μK_CMB² from the extrapolation. This level is the same magnitude as reported by BICEP2 over this ℓ range, which highlights the need for assessment of the polarized dust signal even in the cleanest windows of the sky.