First detection of polarization of the submillimetre diffuse galactic dust emission by Archeops

¹ Centre de Recherche sur les Très Basses Températures, BP166, 38042 Grenoble Cedex 9, France e-mail: benoit@grenoble.cnrs.fr
² Cardiff University, Physics Department, PO Box 913, 5, The Parade, Cardiff, CF24 3YB, UK
³ University of California, Berkeley, Dept. of Astronomy, 601 Campbell Hall, Berkeley, CA 94720-3411, USA
⁴ Laboratoire de l'Accélérateur Linéaire, BP 34, Campus Orsay, 91898 Orsay Cedex, France
⁵ CEA-CE Saclay, DAPNIA, Service de Physique des Particules, Bât. 141, 91191 Gif-sur-Yvette Cedex, France
⁶ Fédération de Recherche APC, Université Paris 7, Paris, France
⁷ Physique Corpusculaire et Cosmologie, Collège de France, 11 pl. M. Berthelot, 75231 Paris Cedex 5, France
⁸ Centre d'Étude Spatiale des Rayonnements, BP 4346, 31028 Toulouse Cedex 4, France
⁹ European Space Agency - ESTEC, Astrophysics Division, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
¹⁰ Laboratoire d'Astrophysique de l'Obs. Midi-Pyrénées, 14 Avenue E. Belin, 31400 Toulouse, France
¹¹ California Institute of Technology, 105-24 Caltech, 1201 East California Blvd, Pasadena CA 91125, USA
¹² Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, California 91109, USA
¹³ IROE–CNR, via Panciatichi, 64, 50127 Firenze, Italy
¹⁴ Institut d'Astrophysique de Paris, 98bis boulevard Arago, 75014 Paris, France
¹⁵ Gruppo di Cosmologia Sperimentale, Dipart. di Fisica, Univ. “La Sapienza”, PA Moro, 2, 00185 Roma, Italy
¹⁶ Laboratoire d'Astrophysique, Obs. de Grenoble, BP 53, 38041 Grenoble Cedex 9, France
¹⁷ Department of Astrophysical Sciences, Peyton Hall - Ivy Lane, Princeton, NJ 08544-1001, USA
¹⁸ Nuclear and Astrophysics Laboratory, Keble Road, Oxford, OX1 3RH, UK
¹⁹ CSNSM–IN2P3, Bât 108, 91405 Orsay Campus, France
²⁰ Infrared Processing and Analysis Center, Caltech, 770 South Wilson Avenue, Pasadena, CA 91125, USA
²¹ Institut d'Astrophysique Spatiale, Bât. 121, Université Paris XI, 91405 Orsay Cedex, France
²² LPNHE, Universités Paris VI et Paris VII, 4 place Jussieu, Tour 33, 75252 Paris Cedex 05, France
²³ School of Physics and Astronomy, 116 Church St SE, University of Minnesota, Minneapolis MN 55455, USA
²⁴ LERMA, Observatoire de Paris, 61 Av. de l'Observatoire, 75014 Paris, France
²⁵ Laboratoire de Physique Subatomique et de Cosmologie, 53 avenue des Martyrs, 38026 Grenoble Cedex, France
²⁶ Experimental Physics, National University of Ireland, Maynooth, Ireland
²⁷ Landau Institute for Theoretical Physics, 119334 Moscow, Russia
²⁸ Space Research Institute, Profsoyuznaya St 84/32, Moscow, Russia
²⁹ CEA-CE Saclay, DAPNIA, Service d'Astrophysique, Bât 709, 91191 Gif-sur-Yvette Cedex, France
³⁰ Laboratoire Leprince-Ringuet, Route de Saclay, 91128 Palaiseau Cedex, France

Received: 11 June 2003
Accepted: 1 October 2003

Abstract

We present the first determination of the Galactic polarized emission at 353 GHz by Archeops. The data were taken during the Arctic night of February 7, 2002 after the balloon-borne instrument was launched by CNES from the Swedish Esrange base near Kiruna. In addition to the 143 GHz and 217 GHz frequency bands dedicated to CMB studies, Archeops had one 545 GHz and six 353 GHz bolometers mounted in three polarization–sensitive pairs that were used for Galactic foreground studies. We present maps of the  Stokes parameters over 17% of the sky and with a 13 arcmin resolution at 353 GHz (). They show a significant Galactic large scale polarized emission coherent on the longitude ranges and  deg. with a degree of polarization at the level of 4–5%, in agreement with expectations from starlight polarization measurements. Some regions in the Galactic plane (Gem OB1, Cassiopeia) show an even stronger degree of polarization in the range 10–20%. These findings provide strong evidence for a powerful grain alignment mechanism throughout the interstellar medium and a coherent magnetic field coplanar to the Galactic plane. This magnetic field pervades even some dense clouds. Extrapolated to high Galactic latitude, these results indicate that interstellar dust polarized emission is the major foreground for PLANCK–HFI CMB polarization measurements.