Planck early results. XV. Spectral energy distributions and radio continuum spectra of northern extragalactic radio sources^⋆,⋆⋆

¹ Aalto University Metsähovi Radio Observatory, Metsähovintie 114, 02540 Kylmälä, Finland
² Agenzia Spaziale Italiana Science Data Center, c/o ESRIN, via Galileo Galilei, Frascati, Italy
³ Agenzia Spaziale Italiana, Viale Liegi 26, Roma, Italy
⁴ Astronomy Department, University of Michigan, 830 Dennison Building, 500 Church Street, Ann Arbor, Michigan 48109-1042, USA
⁵ Astroparticle Physics Laboratory, NASA/Goddard Space Flight Center, Greenbelt, MD 20771, USA
⁶ Astroparticule et Cosmologie, CNRS (UMR7164), Université Denis Diderot Paris 7, Bâtiment Condorcet, 10 rue A. Domon et Léonie Duquet, Paris, France
⁷ Astrophysics Group, Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 0HE, UK
⁸ Atacama Large Millimeter/submillimeter Array, ALMA Santiago Central Offices, Alonso de Cordova 3107, Vitacura, Casilla 763 0355, Santiago, Chile
⁹ Australia Telescope National Facility, CSIRO, PO Box 76, Epping, NSW 1710, Australia
¹⁰ CITA, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8, Canada
¹¹ CNRS, IRAP, 9 Av. colonelRoche, BP 44346, 31028 Toulouse Cedex 4, France
¹² California Institute of Technology, Pasadena, California, USA
¹³ DAMTP, University of Cambridge, Centre for Mathematical Sciences, Wilberforce Road, Cambridge CB3 0WA, UK
¹⁴ DSM/Irfu/SPP, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
¹⁵ DTU Space, National Space Institute, Juliane Mariesvej 30, Copenhagen, Denmark
¹⁶ Departamento de Física, Universidad de Oviedo, Avda. Calvo Sotelo s/n, Oviedo, Spain
¹⁷ Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16802, USA
¹⁸ Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, Ontario, Canada
¹⁹ Department of Physics & Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, Canada
²⁰ Department of Physics, Gustaf Hällströmin katu 2a, University of Helsinki, Helsinki, Finland
²¹ Department of Physics, Purdue University, 525 Northwestern Avenue, West Lafayette, Indiana, USA
²² Department of Physics, University of California, Berkeley, California, USA
²³ Department of Physics, University of California, One Shields Avenue, Davis, California, USA
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 G. Galilei, Università degli Studi di Padova, via Marzolo 8, 35131 Padova, Italy
²⁷ Dipartimento di Fisica M. Merlin dell’Università e del Politecnico di Bari, 70126 Bari, Italy
²⁸ Dipartimento di Fisica, Università degli Studi di Perugia, 06123 Perugia, Italy
²⁹ Dipartimento di Fisica, Università La Sapienza, P. le A. Moro 2, Roma, Italy
³⁰ Dipartimento di Fisica, Università degli Studi di Milano, via Celoria, 16, Milano, Italy
³¹ Dipartimento di Fisica, Università degli Studi di Trieste, via A. Valerio 2, Trieste, Italy
³² Dipartimento di Fisica, Università di Ferrara, via Saragat 1, 44122 Ferrara, Italy
³³ Dipartimento di Fisica, Università di Roma Tor Vergata, via della Ricerca Scientifica 1, Roma, Italy
³⁴ Discovery Center, Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
³⁵ Dpto. Astrofísica, Universidad de La Laguna (ULL), 38206 La Laguna, Tenerife, Spain
³⁶ European Southern Observatory, ESO Vitacura, Alonso de Cordova 3107, Vitacura, Casilla 19001, Santiago, Chile
³⁷ European Space Agency, ESAC, Planck Science Office, Camino bajo del Castillo, s/n, Urbanización Villafranca del Castillo, Villanueva de la Cañada, Madrid, Spain
³⁸ European Space Agency, ESTEC, Keplerlaan 1, 2201 AZ Noordwijk, The Netherlands
³⁹ Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20, 21500 Piikkiö, Finland
⁴⁰ Haverford College Astronomy Department, 370 Lancaster Avenue, Haverford, Pennsylvania, USA
⁴¹ Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki, Helsinki, Finland
⁴² INAF – Osservatorio Astrofisico di Catania, via S. Sofia 78, Catania, Italy
⁴³ INAF – Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, Padova, Italy
⁴⁴ INAF – Osservatorio Astronomico di Roma, via di Frascati 33, Monte Porzio Catone, Italy
⁴⁵ INAF – Osservatorio Astronomico di Trieste, via G.B. Tiepolo 11, Trieste, Italy
⁴⁶ INAF/IASF Bologna, via Gobetti 101, Bologna, Italy
⁴⁷ INAF/IASF Milano, via E. Bassini 15, Milano, Italy
⁴⁸ INRIA, Laboratoire de Recherche en Informatique, Université Paris-Sud 11, Bâtiment 490, 91405 Orsay Cedex, France
⁴⁹ ISDC Data Centre for Astrophysics, University of Geneva, ch. d’Ecogia 16, Versoix, Switzerland
⁵⁰ Imperial College London, Astrophysics group, Blackett Laboratory, Prince Consort Road, London, SW7 2AZ, UK
⁵¹ Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125, USA
⁵² Institut Néel, CNRS, Université Joseph Fourier Grenoble I, 25 rue des Martyrs, Grenoble, France
⁵³ Institut d’Astrophysique Spatiale, CNRS (UMR8617) Université Paris-Sud 11, Bâtiment 121, Orsay, France
⁵⁴ Institut d’Astrophysique de Paris, CNRS UMR7095, Université Pierre & Marie Curie, 98 bis boulevard Arago, Paris, France
⁵⁵ Institut de Radioastronomie Millimétrique (IRAM), Avenida Divina Pastora 7, Local 20, 18012 Granada, Spain
⁵⁶ Institute of Astronomy and Astrophysics, Academia Sinica, Taipei, Taiwan
⁵⁷ Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK
⁵⁸ Institute of Theoretical Astrophysics, University of Oslo, Blindern, Oslo, Norway
⁵⁹ Instituto de Astrofísica de Canarias, C/Vía Láctea s/n, La Laguna, Tenerife, Spain
⁶⁰ Instituto de Física de Cantabria (CSIC-Universidad de Cantabria), Avda. de los Castros s/n, Santander, Spain
⁶¹ Istituto Nazionale di Fisica Nucleare, Sezione di Bari, 70126 Bari, Italy
⁶² Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, 06123 Perugia, Italy
⁶³ Istituto di Fisica delPlasma, CNR-ENEA-EURATOM Association, via R. Cozzi 53, Milano, Italy
⁶⁴ Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Drive, Pasadena, California, USA
⁶⁵ Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
⁶⁶ Kavli Institute for Cosmology Cambridge, Madingley Road, Cambridge, CB3 0HA, UK
⁶⁷ Key Laboratory of Optical Astronomy, National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012, PR China
⁶⁸ LERMA, CNRS, Observatoire de Paris, 61 Avenue de l’Observatoire, Paris, France
⁶⁹ Laboratoire AIM, IRFU/Service d’Astrophysique – CEA/DSM – CNRS – Université Paris Diderot, Bât. 709, CEA-Saclay, 91191 Gif-sur-Yvette Cedex, France
⁷⁰ Laboratoire Traitement et Communication de l’Information, CNRS (UMR 5141) and Télécom ParisTech, 46 rue Barrault, 75634 Paris Cedex 13, France
⁷¹ Laboratoire de Physique Subatomique et de Cosmologie, CNRS/IN2P3, Université Joseph Fourier Grenoble I, Institut National Polytechnique de Grenoble, 53 rue des Martyrs, 38026 Grenoble Cedex, France
⁷² Laboratoire de l’Accélérateur Linéaire, Université Paris-Sud 11, CNRS/IN2P3, Orsay, France
⁷³ Lawrence Berkeley National Laboratory, Berkeley, California, USA
⁷⁴ Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Str. 1, 85741 Garching, Germany
⁷⁵ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn, Germany
⁷⁶ MilliLab, VTT Technical Research Centre of Finland, Tietotie 3, Espoo, Finland
⁷⁷ National University of Ireland, Department of Experimental Physics, Maynooth, Co. Kildare, Ireland
⁷⁸ Niels Bohr Institute, Blegdamsvej 17, Copenhagen, Denmark
⁷⁹ Owens Valley Radio Observatory, Mail code 249-17, California Institute of Technology, 1200 E California Blvd, Pasadena, CA 91125, USA
⁸⁰ SISSA, Astrophysics Sector, via Bonomea 265, 34136 Trieste, Italy
⁸¹ SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory, Blackford Hill, Edinburgh EH9 3HJ, UK
⁸² School of Physics and Astronomy, Cardiff University, Queens Buildings, The Parade, Cardiff, CF24 3AA, UK
⁸³ Space Sciences Laboratory, University of California, Berkeley, California, USA
⁸⁴ Special Astrophysical Observatory, Russian Academy of Sciences, Nizhnij Arkhyz, Zelenchukskiy region, Karachai-Cherkessian Republic 369167, Russia
⁸⁵ Stanford University, Dept of Physics, Varian Physics Bldg, 382 via Pueblo Mall, Stanford, California, USA
⁸⁶ Tuorla Observatory, Department of Physics and Astronomy, University of Turku, Väisäläntie 20, 21500, Piikkiö, Finland
⁸⁷ Université de Toulouse, UPS-OMP, IRAP, 31028 Toulouse Cedex 4, France
⁸⁸ Universities Space Research Association, Stratospheric Observatory for Infrared Astronomy, MS 211-3, Moffett Field, CA 94035, USA
⁸⁹ University of Granada, Departamento de Física Teórica y del Cosmos, Facultad de Ciencias, Granada, Spain
⁹⁰ University of Miami, Knight Physics Building, 1320 Campo Sano Dr., Coral Gables, Florida, USA
⁹¹ W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305, USA
⁹² Warsaw University Observatory, Aleje Ujazdowskie 4, 00-478 Warszawa, Poland

Received: 8 January 2011
Accepted: 28 June 2011

Abstract

Spectral energy distributions (SEDs) and radio continuum spectra are presented for a northern sample of 104 extragalactic radio sources, based on the Planck Early Release Compact Source Catalogue (ERCSC) and simultaneous multifrequency data. The nine Planck frequencies, from 30 to 857 GHz, are complemented by a set of simultaneous observations ranging from radio to gamma-rays. This is the first extensive frequency coverage in the radio and millimetre domains for an essentially complete sample of extragalactic radio sources, and it shows how the individual shocks, each in their own phase of development, shape the radio spectra as they move in the relativistic jet. The SEDs presented in this paper were fitted with second and third degree polynomials to estimate the frequencies of the synchrotron and inverse Compton (IC) peaks, and the spectral indices of low and high frequency radio data, including the Planck ERCSC data, were calculated. SED modelling methods are discussed, with an emphasis on proper, physical modelling of the synchrotron bump using multiple components. Planck ERCSC data also suggest that the original accelerated electron energy spectrum could be much harder than commonly thought, with power-law indexaround 1.5 instead of the canonical 2.5. The implications of this are discussed for the acceleration mechanisms effective in blazar shocks. Furthermore in many cases the Planck data indicate that gamma-ray emission must originate in the same shocks that produce the radio emission.