Abstract
Planck has observed the entire sky from 30 GHz to 857GHz. The observed foreground emission contains contributions from different phases of the interstellar medium (ISM). We have separated the observed Galactic emission into the different gaseous components (atomic, molecular and ionised) in each of a number of Galactocentric rings. This technique provides the necessary information to study dust properties (emissivity, temperature, etc.), as well as other emission mechanisms as a function of Galactic radius. Templates are created for various Galactocentric radii using velocity information from atomic (neutral hydrogen) and molecular (12CO) observations. The ionised template is assumed to be traced by free-free emission as observed by WMAP, while 408 MHz emission is used to trace the synchrotron component. Gas emission not traced by the above templates, namely "dark gas", as evidenced using Planck data, is included as an additional template, the first time such a component has been used in this way. These templates are then correlated with each of the Planck frequency bands, as well as with higher frequency data from IRAS and DIRBE along with radio data at 1.4 GHz. The emission per column density of the gas templates allows us to create distinct spectral energy distributions (SEDs) per Galactocentric ring and in each of the gaseous tracers from 1.4 GHz to 25 THz (12μm). The resulting SEDs allow us to explore the contribution of various emission mechanisms to the Planck signal. Apart from the thermal dust and free-free emission, we have probed the Galaxy for anomalous (e.g., spinning) dust as well as synchrotron emission. We find the dust opacity in the solar neighbourhood, τ/NH = 0.92 ± 0.05 × 10-25 cm2 at 250 μm, with no significant variation with Galactic radius, even though the dust temperature is seen to vary from over 25 K to under 14 K. Furthermore, we show that anomalous dust emission is present in the atomic, molecular and dark gas phases throughout the Galactic disk. Anomalous emission is not clearly detected in the ionised phase, as free-free emission is seen to dominate. The derived dust propeties associated with the dark gas phase are derived but do not allow us to reveal the nature of this phase. For all environments, the anomalous emission is consistent with rotation from polycyclic aromatic hydrocarbons (PAHs) and, according to our simple model, accounts for (25 ± 5)% (statistical) of the total emission at 30 GHz.
| Original language | English (US) |
|---|---|
| Article number | A21 |
| Journal | Astronomy and Astrophysics |
| Volume | 536 |
| DOIs | |
| State | Published - 2011 |
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science
Keywords
- Galaxy: general
- ISM: general
- Infrared: ISM
- Radiation mechanisms: general
- Radio continuum: ISM
- Submillimeter: ISM
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In: Astronomy and Astrophysics, Vol. 536, A21, 2011.
Research output: Contribution to journal › Article › peer-review
TY - JOUR
T1 - Planck early results. XXI. Properties of the interstellar medium in the Galactic plane
AU - Abergel, A.
AU - Ade, P. A.R.
AU - Aghanim, N.
AU - Arnaud, M.
AU - Ashdown, M.
AU - Aumont, J.
AU - Baccigalupi, C.
AU - Balbi, A.
AU - Banday, A. J.
AU - Barreiro, R. B.
AU - Bartlett, J. G.
AU - Battaner, E.
AU - Benabed, K.
AU - Benoît, A.
AU - Bernard, J. P.
AU - Bersanelli, M.
AU - Bhatia, R.
AU - Bock, J. J.
AU - Bonaldi, A.
AU - Bond, J. R.
AU - Borrill, J.
AU - Bouchet, F. R.
AU - Boulanger, F.
AU - Bucher, M.
AU - Burigana, C.
AU - Cabella, P.
AU - Cardoso, J. F.
AU - Catalano, A.
AU - Cayón, L.
AU - Challinor, A.
AU - Chamballu, A.
AU - Chiang, L. Y.
AU - Chiang, C.
AU - Christensen, P. R.
AU - Colombi, S.
AU - Couchot, F.
AU - Coulais, A.
AU - Crill, B. P.
AU - Cuttaia, F.
AU - Dame, T. M.
AU - Danese, L.
AU - Davies, R. D.
AU - Davis, R. J.
AU - De Bernardis, P.
AU - De Gasperis, G.
AU - De Rosa, A.
AU - De Zotti, G.
AU - Delabrouille, J.
AU - Delouis, J. M.
AU - Désert, F. X.
AU - Dickinson, C.
AU - Donzelli, S.
AU - Doré, O.
AU - Dörl, U.
AU - Douspis, M.
AU - Dupac, X.
AU - Efstathiou, G.
AU - Enßlin, T. A.
AU - Finelli, F.
AU - Forni, O.
AU - Frailis, M.
AU - Franceschi, E.
AU - Galeotta, S.
AU - Ganga, K.
AU - Giard, M.
AU - Giardino, G.
AU - Giraud-Héraud, Y.
AU - González-Nuevo, J.
AU - Górski, K. M.
AU - Gratton, S.
AU - Gregorio, A.
AU - Grenier, I. A.
AU - Gruppuso, A.
AU - Hansen, F. K.
AU - Harrison, D.
AU - Henrot-Versillé, S.
AU - Herranz, D.
AU - Hildebrandt, S. R.
AU - Hivon, E.
AU - Hobson, M.
AU - Holmes, W. A.
AU - Hovest, W.
AU - Hoyland, R. J.
AU - Huffenberger, K. M.
AU - Jaffe, T. R.
AU - Jaffe, A. H.
AU - Jones, W. C.
AU - Juvela, M.
AU - Keihänen, E.
AU - Keskitalo, R.
AU - Kisner, T. S.
AU - Kneissl, R.
AU - Knox, L.
AU - Kurki-Suonio, H.
AU - Lagache, G.
AU - Lähteenmäki, A.
AU - Lamarre, J. M.
AU - Lasenby, A.
AU - Laureijs, R. J.
AU - Lawrence, C. R.
AU - Leach, S.
AU - Leonardi, R.
AU - Leroy, C.
AU - Lilje, P. B.
AU - Linden-Vørnle, M.
AU - López-Caniego, M.
AU - Lubin, P. M.
AU - MacÍas-Pérez, J. F.
AU - MacTavish, C. J.
AU - Maffei, B.
AU - Mandolesi, N.
AU - Mann, R.
AU - Maris, M.
AU - Marshall, D. J.
AU - Martínez-González, E.
AU - Masi, S.
AU - Matarrese, S.
AU - Matthai, F.
AU - Mazzotta, P.
AU - McGehee, P.
AU - Meinhold, P. R.
AU - Melchiorri, A.
AU - Mendes, L.
AU - Mennella, A.
AU - Miville-Deschênes, M. A.
AU - Moneti, A.
AU - Montier, L.
AU - Morgante, G.
AU - Mortlock, D.
AU - Munshi, D.
AU - Murphy, A.
AU - Naselsky, P.
AU - Natoli, P.
AU - Netterfield, C. B.
AU - Nørgaard-Nielsen, H. U.
AU - Noviello, F.
AU - Novikov, D.
AU - Novikov, I.
AU - Osborne, S.
AU - Pajot, F.
AU - Paladini, R.
AU - Pasian, F.
AU - Patanchon, G.
AU - Perdereau, O.
AU - Perotto, L.
AU - Perrotta, F.
AU - Piacentini, F.
AU - Piat, M.
AU - Plaszczynski, S.
AU - Pointecouteau, E.
AU - Polenta, G.
AU - Ponthieu, N.
AU - Poutanen, T.
AU - Prézeau, G.
AU - Prunet, S.
AU - Puget, J. L.
AU - Rachen, J. P.
AU - Reach, W. T.
AU - Rebolo, R.
AU - Reich, W.
AU - Renault, C.
AU - Ricciardi, S.
AU - Riller, T.
AU - Ristorcelli, I.
AU - Rocha, G.
AU - Rosset, C.
AU - Rubiño-Martín, J. A.
AU - Rusholme, B.
AU - Sandri, M.
AU - Santos, D.
AU - Savini, G.
AU - Scott, D.
AU - Seiffert, M. D.
AU - Shellard, P.
AU - Smoot, G. F.
AU - Starck, J. L.
AU - Stivoli, F.
AU - Stolyarov, V.
AU - Stompor, R.
AU - Sudiwala, R.
AU - Sygnet, J. F.
AU - Tauber, J. A.
AU - Terenzi, L.
AU - Toffolatti, L.
AU - Tomasi, M.
AU - Torre, J. P.
AU - Tristram, M.
AU - Tuovinen, J.
AU - Umana, G.
AU - Valenziano, L.
AU - Varis, J.
AU - Vielva, P.
AU - Villa, F.
AU - Vittorio, N.
AU - Wade, L. A.
AU - Wandelt, B. D.
AU - Wilkinson, A.
AU - Ysard, N.
AU - Yvon, D.
AU - Zacchei, A.
AU - Zonca, A.
N1 - Funding Information: 0004-6361 1432-0746 EDP Sciences 10.1051/0004-6361/201116455 aa16455-11 2011A%26A...536A..21P Planck early results Interstellar and circumstellar matter Planck early results. XXI. Properties of the interstellar medium in the Galactic plane ⋆ ⋆ Corresponding author: D. J. Marshall, e-mail: [email protected] Planck Collaboration Abergel A. 47 Ade P. A. R. 72 Aghanim N. 47 Arnaud M. 58 Ashdown M. 56 4 Aumont J. 47 Baccigalupi C. 70 Balbi A. 28 Banday A. J. 76 7 63 Barreiro R. B. 53 Bartlett J. G. 3 54 Battaner E. 78 Benabed K. 48 Benoît A. 46 Bernard J.-P. 76 7 Bersanelli M. 25 41 Bhatia R. 5 Bock J. J. 54 8 Bonaldi A. 37 Bond J. R. 6 Borrill J. 62 73 Bouchet F. R. 48 Boulanger F. 47 Bucher M. 3 Burigana C. 40 Cabella P. 28 Cardoso J.-F. 59 3 48 Catalano A. 3 57 Cayón L. 18 Challinor A. 50 56 10 Chamballu A. 44 Chiang L.-Y 49 Chiang C. 17 Christensen P. R. 67 29 Colombi S. 48 Couchot F. 61 Coulais A. 57 Crill B. P. 54 68 Cuttaia F. 40 Dame T. M. 34 Danese L. 70 Davies R. D. 55 Davis R. J. 55 de Bernardis P. 24 de Gasperis G. 28 de Rosa A. 40 de Zotti G. 37 70 Delabrouille J. 3 Delouis J.-M. 48 Désert F.-X. 43 Dickinson C. 55 Donzelli S. 41 51 Doré O. 54 8 Dörl U. 63 Douspis M. 47 Dupac X. 32 Efstathiou G. 50 Enßlin T. A. 63 Finelli F. 40 Forni O. 76 7 Frailis M. 39 Franceschi E. 40 Galeotta S. 39 Ganga K. 3 45 Giard M. 76 7 Giardino G. 33 Giraud-Héraud Y. 3 González-Nuevo J. 70 Górski K. M. 54 80 Gratton S. 56 50 Gregorio A. 26 Grenier I. A. 58 Gruppuso A. 40 Hansen F. K. 51 Harrison D. 50 56 Henrot-Versillé S. 61 Herranz D. 53 Hildebrandt S. R. 8 60 52 Hivon E. 48 Hobson M. 4 Holmes W. A. 54 Hovest W. 63 Hoyland R. J. 52 Huffenberger K. M. 79 Jaffe T. R. 76 7 Jaffe A. H. 44 Jones W. C. 17 Juvela M. 16 Keihänen E. 16 Keskitalo R. 54 16 Kisner T. S. 62 Kneissl R. 31 5 Knox L. 20 Kurki-Suonio H. 16 35 Lagache G. 47 Lähteenmäki A. 1 35 Lamarre J.-M. 57 Lasenby A. 4 56 Laureijs R. J. 33 Lawrence C. R. 54 Leach S. 70 Leonardi R. 32 33 21 Leroy C. 47 76 7 Lilje P. B. 51 9 Linden-Vørnle M. 12 López-Caniego M. 53 Lubin P. M. 21 Macías-Pérez J. F. 60 MacTavish C. J. 56 Maffei B. 55 Mandolesi N. 40 Mann R. 71 Maris M. 39 Marshall D. J. 76 7 Martínez-González E. 53 Masi S. 24 Matarrese S. 23 Matthai F. 63 Mazzotta P. 28 McGehee P. 45 Meinhold P. R. 21 Melchiorri A. 24 Mendes L. 32 Mennella A. 25 39 Miville-Deschênes M.-A. 47 6 Moneti A. 48 Montier L. 76 7 Morgante G. 40 Mortlock D. 44 Munshi D. 72 50 Murphy A. 66 Naselsky P. 67 29 Natoli P. 27 2 40 Netterfield C. B. 14 Nørgaard-Nielsen H. U. 12 Noviello F. 47 Novikov D. 44 Novikov I. 67 Osborne S. 75 Pajot F. 47 Paladini R. 74 8 Pasian F. 39 Patanchon G. 3 Perdereau O. 61 Perotto L. 60 Perrotta F. 70 Piacentini F. 24 Piat M. 3 Plaszczynski S. 61 Pointecouteau E. 76 7 Polenta G. 2 38 Ponthieu N. 47 Poutanen T. 35 16 1 Prézeau G. 8 54 Prunet S. 48 Puget J.-L. 47 Rachen J. P. 63 Reach W. T. 77 Rebolo R. 52 30 Reich W. 64 Renault C. 60 Ricciardi S. 40 Riller T. 63 Ristorcelli I. 76 7 Rocha G. 54 8 Rosset C. 3 Rubiño-Martín J. A. 52 30 Rusholme B. 45 Sandri M. 40 Santos D. 60 Savini G. 69 Scott D. 15 Seiffert M. D. 54 8 Shellard P. 10 Smoot G. F. 19 62 3 Starck J.-L. 58 11 Stivoli F. 42 Stolyarov V. 4 Stompor R. 3 Sudiwala R. 72 Sygnet J.-F. 48 Tauber J. A. 33 Terenzi L. 40 Toffolatti L. 13 Tomasi M. 25 41 Torre J.-P. 47 Tristram M. 61 Tuovinen J. 65 Umana G. 36 Valenziano L. 40 Varis J. 65 Vielva P. 53 Villa F. 40 Vittorio N. 28 Wade L. A. 54 Wandelt B. D. 48 22 Wilkinson A. 55 Ysard N. 16 Yvon D. 11 Zacchei A. 39 Zonca A. 21 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 Astroparticule et Cosmologie, CNRS (UMR7164), Université Denis Diderot Paris 7 , Bâtiment Condorcet, 10 rue A. Domon et Léonie Duquet , Paris , France 4 Astrophysics Group, Cavendish Laboratory, University of Cambridge , J J Thomson Avenue , Cambridge CB3 0HE , UK 5 Atacama Large Millimeter/submillimeter Array, ALMA Santiago Central Offices , Alonso de Cordova 3107, Vitacura , Casilla 763 0355 , Santiago , Chile 6 CITA, University of Toronto , 60 St. George St., Toronto , ON M5S 3H8 , Canada 7 CNRS, IRAP , 9 Av. colonel Roche , BP 44346 , 31028 Toulouse Cedex 4 , France 8 California Institute of Technology , Pasadena , California , USA 9 Centre of Mathematics for Applications, University of Oslo , Blindern , Oslo , Norway 10 DAMTP, University of Cambridge, Centre for Mathematical Sciences , Wilberforce Road , Cambridge CB3 0WA , UK 11 DSM/Irfu/SPP, CEA-Saclay , 91191 Gif-sur-Yvette Cedex , France 12 DTU Space, National Space Institute , Juliane Mariesvej 30 , Copenhagen , Denmark 13 Departamento de Física, Universidad de Oviedo , Avda. Calvo Sotelo s/n , Oviedo , Spain 14 Department of Astronomy and Astrophysics, University of Toronto , 50 Saint George Street, Toronto , Ontario , Canada 15 Department of Physics & Astronomy, University of British Columbia , 6224 Agricultural Road, Vancouver , British Columbia , Canada 16 Department of Physics, Gustaf Hällströmin katu 2a, University of Helsinki , Helsinki , Finland 17 Department of Physics, Princeton University , Princeton , New Jersey , USA 18 Department of Physics, Purdue University , 525 Northwestern Avenue , West Lafayette , Indiana , USA 19 Department of Physics, University of California , Berkeley , California , USA 20 Department of Physics, University of California , One Shields Avenue , Davis , California , USA 21 Department of Physics, University of California , Santa Barbara , California , USA 22 Department of Physics, University of Illinois at Urbana-Champaign , 1110 West Green Street , Urbana , Illinois , USA 23 Dipartimento di Fisica G. Galilei, Università degli Studi di Padova , via Marzolo 8 , 35131 Padova , Italy 24 Dipartimento di Fisica, Università La Sapienza , P. le A. Moro 2 , Roma , Italy 25 Dipartimento di Fisica, Università degli Studi di Milano , via Celoria 16 , Milano , Italy 26 Dipartimento di Fisica, Università degli Studi di Trieste , via A. Valerio 2 , Trieste , Italy 27 Dipartimento di Fisica, Università di Ferrara , via Saragat 1 , 44122 Ferrara , Italy 28 Dipartimento di Fisica, Università di Roma Tor Vergata , viadella Ricerca Scientifica 1 , Roma , Italy 29 Discovery Center, Niels Bohr Institute , Blegdamsvej 17 , Copenhagen , Denmark 30 Dpto. Astrofísica, Universidad de La Laguna (ULL) , 38206 La Laguna , Tenerife , Spain 31 European Southern Observatory, ESO Vitacura , Alonso de Cordova 3107, Vitacura, Casilla 19001 , Santiago , Chile 32 European Space Agency, ESAC, Planck Science Office, Camino bajo del Castillo, s/n, Urbanización Villafranca del Castillo, Villanueva de la Cañada , Madrid , Spain 33 European Space Agency, ESTEC , Keplerlaan 1 , 2201 AZ Noordwijk , The Netherlands 34 Harvard-Smithsonian Center for Astrophysics , 60 Garden Street , Cambridge , MA 02138 , USA 35 Helsinki Institute of Physics, Gustaf Hällströmin katu 2, University of Helsinki , Helsinki , Finland 36 INAF - Osservatorio Astrofisico di Catania , via S. Sofia 78 , Catania , Italy 37 INAF - Osservatorio Astronomico di Padova , Vicolo dell’Osservatorio 5 , Padova , Italy 38 INAF - Osservatorio Astronomico di Roma , via di Frascati 33 , Monte Porzio Catone , Italy 39 INAF - Osservatorio Astronomico di Trieste , via G.B. Tiepolo 11 , Trieste , Italy 40 INAF/IASF Bologna , via Gobetti 101 , Bologna , Italy 41 INAF/IASF Milano , via E. Bassini 15 , Milano , Italy 42 INRIA, Laboratoire de Recherche en Informatique, Université Paris-Sud 11 , Bâtiment 490 , 91405 Orsay Cedex , France 43 IPAG: Institut de Planétologie et d’Astrophysique de Grenoble, Université Joseph Fourier, Grenoble 1/CNRS-INSU, UMR 5274 , 38041 Grenoble , France 44 Imperial College London, Astrophysics group, Blackett Laboratory , Prince Consort Road , London , SW7 2AZ , UK 45 Infrared Processing and Analysis Center, California Institute of Technology , Pasadena , CA 91125 , USA 46 Institut Néel, CNRS, Université Joseph Fourier Grenoble I , 25 rue des Martyrs , Grenoble , France 47 Institut d’Astrophysique Spatiale, CNRS (UMR8617) Université Paris-Sud 11 , Bâtiment 121 , Orsay , France 48 Institut d’Astrophysique de Paris, CNRS UMR7095, Université Pierre & Marie Curie , 98 bis boulevard Arago , Paris , France 49 Institute of Astronomy and Astrophysics, Academia Sinica , Taipei , Taiwan 50 Institute of Astronomy, University of Cambridge , Madingley Road , Cambridge CB3 0HA , UK 51 Institute of Theoretical Astrophysics, University of Oslo , Blindern , Oslo , Norway 52 Instituto de Astrofísica de Canarias , C/vía Láctea s/n, La Laguna , Tenerife , Spain 53 Instituto de Física de Cantabria (CSIC-Universidad de Cantabria) , Avda. de los Castros s/n , Santander , Spain 54 Jet Propulsion Laboratory, California Institute of Technology , 4800 Oak Grove Drive , Pasadena , California , USA 55 Jodrell Bank Centre for Astrophysics, Alan Turing Building, School of Physics and Astronomy, The University of Manchester , Oxford Road , Manchester , M13 9PL , UK 56 Kavli Institute for Cosmology Cambridge , Madingley Road , Cambridge , CB3 0HA , UK 57 LERMA, CNRS, Observatoire de Paris , 61 Avenue de l’Observatoire , Paris , France 58 Laboratoire AIM, IRFU/Service d’Astrophysique - CEA/DSM - CNRS - Université Paris Diderot, Bât. 709, CEA-Saclay , 91191 Gif-sur-Yvette Cedex , France 59 Laboratoire Traitement et Communication de l’Information, CNRS (UMR 5141) and Télécom ParisTech , 46 rue Barrault , 75634 Paris Cedex 13 , France 60 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 61 Laboratoire de l’Accélérateur Linéaire, Université Paris-Sud 11, CNRS/IN2P3 , Orsay , France 62 Lawrence Berkeley National Laboratory , Berkeley , California , USA 63 Max-Planck-Institut für Astrophysik , Karl-Schwarzschild-Str. 1 , 85741 Garching , Germany 64 Max-Planck-Institut für Radioastronomie , Auf dem Hügel 69 , 53121 Bonn , Germany 65 MilliLab, VTT Technical Research Centre of Finland , Tietotie 3 , Espoo , Finland 66 National University of Ireland, Department of Experimental Physics , Maynooth , Co. Kildare , Ireland 67 Niels Bohr Institute , Blegdamsvej 17 , Copenhagen , Denmark 68 Observational Cosmology, Mail Stop 367-17, California Institute of Technology , Pasadena , CA 91125 , USA 69 Optical Science Laboratory, University College London , Gower Street , London , UK 70 SISSA, Astrophysics Sector , via Bonomea 265 , 34136 Trieste , Italy 71 SUPA, Institute for Astronomy, University of Edinburgh, Royal Observatory , Blackford Hill , Edinburgh EH9 3HJ , UK 72 School of Physics and Astronomy, Cardiff University , Queens Buildings, The Parade , Cardiff , CF24 3AA , UK 73 Space Sciences Laboratory, University of California , Berkeley , California , USA 74 Spitzer Science Center , 1200 E. California Blvd. , Pasadena , California , USA 75 Stanford University, Dept of Physics, Varian Physics Bldg , , 382 Via Pueblo Mall , Stanford , California , USA 76 Université de Toulouse, UPS-OMP, IRAP , 31028 Toulouse Cedex 4 , France 77 Universities Space Research Association, Stratospheric Observatory for Infrared Astronomy , MS 211-3 , Moffett Field , CA 94035 , USA 78 University of Granada, Departamento de Física Teórica y del Cosmos, Facultad de Ciencias , Granada , Spain 79 University of Miami, Knight Physics Building , 1320 Campo Sano Dr. , Coral Gables , Florida , USA 80 Warsaw University Observatory , Aleje Ujazdowskie 4 , 00-478 Warszawa , Poland 01 12 2011 01 12 2011 12 2011 536 aa/2011/12
PY - 2011
Y1 - 2011
N2 - Planck has observed the entire sky from 30 GHz to 857GHz. The observed foreground emission contains contributions from different phases of the interstellar medium (ISM). We have separated the observed Galactic emission into the different gaseous components (atomic, molecular and ionised) in each of a number of Galactocentric rings. This technique provides the necessary information to study dust properties (emissivity, temperature, etc.), as well as other emission mechanisms as a function of Galactic radius. Templates are created for various Galactocentric radii using velocity information from atomic (neutral hydrogen) and molecular (12CO) observations. The ionised template is assumed to be traced by free-free emission as observed by WMAP, while 408 MHz emission is used to trace the synchrotron component. Gas emission not traced by the above templates, namely "dark gas", as evidenced using Planck data, is included as an additional template, the first time such a component has been used in this way. These templates are then correlated with each of the Planck frequency bands, as well as with higher frequency data from IRAS and DIRBE along with radio data at 1.4 GHz. The emission per column density of the gas templates allows us to create distinct spectral energy distributions (SEDs) per Galactocentric ring and in each of the gaseous tracers from 1.4 GHz to 25 THz (12μm). The resulting SEDs allow us to explore the contribution of various emission mechanisms to the Planck signal. Apart from the thermal dust and free-free emission, we have probed the Galaxy for anomalous (e.g., spinning) dust as well as synchrotron emission. We find the dust opacity in the solar neighbourhood, τ/NH = 0.92 ± 0.05 × 10-25 cm2 at 250 μm, with no significant variation with Galactic radius, even though the dust temperature is seen to vary from over 25 K to under 14 K. Furthermore, we show that anomalous dust emission is present in the atomic, molecular and dark gas phases throughout the Galactic disk. Anomalous emission is not clearly detected in the ionised phase, as free-free emission is seen to dominate. The derived dust propeties associated with the dark gas phase are derived but do not allow us to reveal the nature of this phase. For all environments, the anomalous emission is consistent with rotation from polycyclic aromatic hydrocarbons (PAHs) and, according to our simple model, accounts for (25 ± 5)% (statistical) of the total emission at 30 GHz.
AB - Planck has observed the entire sky from 30 GHz to 857GHz. The observed foreground emission contains contributions from different phases of the interstellar medium (ISM). We have separated the observed Galactic emission into the different gaseous components (atomic, molecular and ionised) in each of a number of Galactocentric rings. This technique provides the necessary information to study dust properties (emissivity, temperature, etc.), as well as other emission mechanisms as a function of Galactic radius. Templates are created for various Galactocentric radii using velocity information from atomic (neutral hydrogen) and molecular (12CO) observations. The ionised template is assumed to be traced by free-free emission as observed by WMAP, while 408 MHz emission is used to trace the synchrotron component. Gas emission not traced by the above templates, namely "dark gas", as evidenced using Planck data, is included as an additional template, the first time such a component has been used in this way. These templates are then correlated with each of the Planck frequency bands, as well as with higher frequency data from IRAS and DIRBE along with radio data at 1.4 GHz. The emission per column density of the gas templates allows us to create distinct spectral energy distributions (SEDs) per Galactocentric ring and in each of the gaseous tracers from 1.4 GHz to 25 THz (12μm). The resulting SEDs allow us to explore the contribution of various emission mechanisms to the Planck signal. Apart from the thermal dust and free-free emission, we have probed the Galaxy for anomalous (e.g., spinning) dust as well as synchrotron emission. We find the dust opacity in the solar neighbourhood, τ/NH = 0.92 ± 0.05 × 10-25 cm2 at 250 μm, with no significant variation with Galactic radius, even though the dust temperature is seen to vary from over 25 K to under 14 K. Furthermore, we show that anomalous dust emission is present in the atomic, molecular and dark gas phases throughout the Galactic disk. Anomalous emission is not clearly detected in the ionised phase, as free-free emission is seen to dominate. The derived dust propeties associated with the dark gas phase are derived but do not allow us to reveal the nature of this phase. For all environments, the anomalous emission is consistent with rotation from polycyclic aromatic hydrocarbons (PAHs) and, according to our simple model, accounts for (25 ± 5)% (statistical) of the total emission at 30 GHz.
KW - Galaxy: general
KW - ISM: general
KW - Infrared: ISM
KW - Radiation mechanisms: general
KW - Radio continuum: ISM
KW - Submillimeter: ISM
UR - http://www.scopus.com/inward/record.url?scp=80055014497&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=80055014497&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201116455
DO - 10.1051/0004-6361/201116455
M3 - Article
AN - SCOPUS:80055014497
SN - 0004-6361
VL - 536
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A21
ER -