Planck intermediate results. XII: Diffuse Galactic components in the Gould Belt system ^⋆

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 Aalto University Metsähovi Radio Observatory, Metsähovintie 114, 02540 Kylmälä, Finland
³ African Institute for Mathematical Sciences, 6-8 Melrose Road, Muizenberg, Cape Town, South Africa
⁴ Agenzia Spaziale Italiana Science Data Center, c/o ESRIN, via Galileo Galilei, Frascati, Italy
⁵ Agenzia Spaziale Italiana, Viale Liegi 26, Roma, Italy
⁶ Astrophysics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
⁷ CITA, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8, Canada
⁸ CNR – ISTI, Area della Ricerca, via G. Moruzzi 1, Pisa, Italy
⁹ CNRS, IRAP, 9 Av. colonel Roche, BP 44346, 31028 Toulouse Cedex 4, France
¹⁰ California Institute of Technology, Pasadena, California, USA
¹¹ Centro de Estudios de Física del Cosmos de Aragón (CEFCA), Plaza San Juan, 1, planta 2, 44001 Teruel, Spain
¹² Computational Cosmology Center, Lawrence Berkeley National Laboratory, Berkeley, California, USA
¹³ Consejo Superior de Investigaciones Científicas (CSIC), Madrid, Spain
¹⁴ DSM/Irfu/SPP, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
¹⁵ DTU Space, National Space Institute, Technical University of Denmark, Elektrovej 327, 2800 Kgs. Lyngby, Denmark
¹⁶ Département de Physique Théorique, Université de Genève, 24 Quai E. Ansermet, 1211 Genève 4, Switzerland
¹⁷ Departamento de Física Fundamental, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca, Spain
¹⁸ Departamento de Física, Universidad de Oviedo, Avda. Calvo Sotelo s/n, Oviedo, Spain
¹⁹ Department of Astrophysics/IMAPP, Radboud University Nijmegen, PO Box 9010, 6500 GL Nijmegen, The Netherlands
²⁰ Department of Electrical Engineering and Computer Sciences, University of California, Berkeley, California, USA
²¹ Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, Canada
²² Department of Physics and Astronomy,Dana and David Dornsife College of Letter, Arts and Sciences, University of Southern California, Los Angeles, CA 90089, USA
²³ Department of Physics, Gustaf Hällströmin katu 2a, University of Helsinki, Helsinki, Finland
²⁴ Department of Physics, University of California, Santa Barbara, California, USA
²⁵ Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green Street, Urbana, Illinois, USA
²⁶ Dipartimento di Fisica e Astronomia G. Galilei, Università degli Studi di Padova, via Marzolo 8, 35131 Padova, Italy
²⁷ Dipartimento di Fisica e Scienze della Terra, Università di Ferrara, via Saragat 1, 44122 Ferrara, Italy
²⁸ Dipartimento di Fisica, Università La Sapienza, P. le A. Moro 2, Roma, Italy
²⁹ Dipartimento di Fisica, Università degli Studi di Milano, via Celoria 16, Milano, Italy
³⁰ Dipartimento di Fisica, Università degli Studi di Trieste, via A. Valerio 2, Trieste, Italy
³¹ Dipartimento di Fisica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
³² Dipartimento di Matematica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
³³ Discovery Center, Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
³⁴ Dpto. Astrofísica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Spain
³⁵ European Space Agency, ESAC, Planck Science Office, Camino bajo del Castillo, s/n, Urbanización Villafranca del Castillo, Villanueva de la Cañada, Madrid, Spain
³⁶ European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
³⁷ Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki, Helsinki, Finland
³⁸ INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova, Italy
³⁹ INAF – Osservatorio Astronomico di Roma, via di Frascati 33, Monte Porzio Catone, Italy
⁴⁰ INAF – Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, Trieste, Italy
⁴¹ INAF Istituto di Radioastronomia, via P. Gobetti 101, 40129 Bologna, Italy
⁴² INAF/IASF Bologna, via Gobetti, 101, Bologna, Italy
⁴³ INAF/IASF Milano, via E. Bassini 15, Milano, Italy
⁴⁴ INFN, Sezione di Bologna, via Irnerio 46, 40126 Bologna, Italy
⁴⁵ INFN, Sezione di Roma 1, Universit‘a di Roma Sapienza, Piazzale Aldo Moro 2, 00185 Roma, Italy
⁴⁶ IUCAA, Post Bag 4, Ganeshkhind, Pune University Campus, 411 007 Pune, India
⁴⁷ Imperial College London, Astrophysics group, Blackett Laboratory, Prince Consort Road, London, SW7 2AZ, UK
⁴⁸ Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA
⁴⁹ Institut Néel, CNRS, Université Joseph Fourier Grenoble I, 25 rue des Martyrs, Grenoble, France
⁵⁰ Institut Universitaire de France, 103 bd Saint-Michel, 75005 Paris, France
⁵¹ Institut d’Astrophysique Spatiale, CNRS (UMR 8617) Université Paris-Sud 11, Bâtiment 121, Orsay, France
⁵² Institut d’Astrophysique de Paris, CNRS (UMR 7095), 98 bis Boulevard Arago, 75014 Paris, France
⁵³ Institute for Space Sciences, Bucharest-Magurale, Romania
⁵⁴ Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan
⁵⁵ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁵⁶ Institute of Theoretical Astrophysics, University of Oslo, Blindern, Oslo, Norway
⁵⁷ Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, La Laguna, Tenerife, Spain
⁵⁸ Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), Avda. de los Castros s/n, Santander, Spain
⁵⁹ Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, USA
⁶⁰ Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
⁶¹ Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
⁶² Kavli Institute for Theoretical Physics, University of California, Santa Barbara Kohn Hall, Santa Barbara, CA 93106, USA
⁶³ LAL, Université Paris-Sud, CNRS/IN2P3, Orsay, France
⁶⁴ LERMA, CNRS, Observatoire de Paris, 61 Avenue de l’Observatoire, Paris, France
⁶⁵ Laboratoire AIM, IRFU/Service d’Astrophysique – CEA/DSM – CNRS – Université Paris Diderot, Bât. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
⁶⁶ Laboratoire Traitement et Communication de l’Information, CNRS (UMR 5141) and Télécom ParisTech, 46 rue Barrault, 75634 Paris Cedex 13, France
⁶⁷ 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
⁶⁸ Laboratoire de Physique Théorique, Université Paris-Sud 11 & CNRS, Bâtiment 210, 91405 Orsay, France
⁶⁹ Lawrence Berkeley National Laboratory, Berkeley, California, USA
⁷⁰ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
⁷¹ MilliLab, VTT Technical Research Centre of Finland, Tietotie 3, Espoo, Finland
⁷² National University of Ireland, Department of Experimental Physics, Maynooth, Co. Kildare, Ireland
⁷³ Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
⁷⁴ Optical Science Laboratory, University College London, Gower Street, London, UK
⁷⁵ SISSA, Astrophysics Sector, via Bonomea 265, 34136 Trieste, Italy
⁷⁶ School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, CF24 3AA, UK
⁷⁷ Space Sciences Laboratory, University of California, Berkeley, California, USA
⁷⁸ Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Zelenchukskiy region, 369167 Karachai-Cherkessian Republic, Russia
⁷⁹ Stanford University, Dept of Physics, Varian Physics Bldg, 382 via Pueblo Mall, Stanford, California, USA
⁸⁰ UPMC Univ Paris 06, UMR 7095, 98bis Boulevard Arago, 75014 Paris, France
⁸¹ Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse Cedex 4, France
⁸² Universities Space Research Association, Stratospheric Observatory for Infrared Astronomy, MS 232-11, Moffett Field, CA 94035, USA
⁸³ University of Granada, Departamento de Física Teórica y del Cosmos, Facultad de Ciencias, Granada, Spain
⁸⁴ University of Miami, Knight Physics Building, 1320 Campo Sano Dr. Coral Gables, Florida, USA
⁸⁵ Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland

Received: 24 January 2013
Accepted: 31 May 2013

Abstract

We perform an analysis of the diffuse low-frequency Galactic components in the southern part of the Gould Belt system (130° ≤ l ≤ 230° and −50° ≤ b ≤ −10°). Strong ultra-violet flux coming from the Gould Belt super-association is responsible for bright diffuse foregrounds that we observe from our position inside the system and that can help us improve our knowledge of the Galactic emission. Free-free emission and anomalous microwave emission (AME) are the dominant components at low frequencies (ν < 40 GHz), while synchrotron emission is very smooth and faint. We separated diffuse free-free emission and AME from synchrotron emission and thermal dust emission by using Planck data, complemented by ancillary data, using the correlated component analysis (CCA) component-separation method and we compared our results with the results of cross-correlation of foreground templates with the frequency maps. We estimated the electron temperature T_e from Hα and free-free emission using two methods (temperature-temperature plot and cross-correlation) and obtained T_e ranging from 3100 to 5200K for an effective fraction of absorbing dust along the line of sight of 30% (f_d = 0.3). We estimated the frequency spectrum of the diffuse AME and recovered a peak frequency (in flux density units) of 25.5 ± 1.5 GHz. We verified the reliability of this result with realistic simulations that include biases in the spectral model for the AME and in the free-free template. By combining physical models for vibrational and rotational dust emission and adding the constraints from the thermal dust spectrum from Planck and IRAS, we are able to present a good description of the AME frequency spectrum for plausible values of the local density and radiation field.