Planck intermediate results XLV. Radio spectra of northern extragalactic radio sources
: Ade PAR, Aghanim N, Aller HD, Aller MF, Arnaud M, Aumont J, Baccigalupi C, Banday AJ, Barreiro RB, Bartolo N, Battaner E, Benabed K, Benoit-Levy A, Bernard JP, Bersanelli M, Bielewicz P, Bonaldi A, Bonavera L, Bond JR, Borrill J, Bouchet FR, Burigana C, Calabrese E, Catalano A, Chiang HC, Christensen PR, Clements DL, Colomb LPL, Couchot F, Crill BP, Curto A, Cuttaia F, Danese L, Davies RD, Davis RJ, de Bernardis P, de Rosa A, de Zotti G, Delabrouille J, Dickinson C, Diego JM, Dole H, Donzelli S, Dore O, Ducout A, Dupac X, Efstathiou G, Elsner F, Eriksen HK, Finelli F, Forni O, Frailis M, Fraisse AA, Franceschi E, Galeotta S, Galli S, Ganga K, Giard M, Giraud-Heraud Y, Gjerlow E, Gonzalez-Nuevo J, Gorski KM, Gruppuso A, Gurwel MA, Hansen FK, Harrison DL, Henrot-Versille S, Hernandez-Monteagudo C, Hildebrandt SR, Hobson M, Hornstrup A, Hovatta T, Hovest W, Huffenberger KM, Hurier G, Jaffe AH, Jaffe TR, Jarvela E, Keihanen E, Keskitalo R, Kisner TS, Kneiss R, Knoche J, Kunz M, Kurki-Suonio H, Lahteenmaki A, Lamarre JM, Lasenby A, Lattanzi M, Lawrence CR, Leonardi R, Levrier F, Liguori M, Lilje PB, Linden-Vornle M, Lopez-Caniego M, Lubin PM, Macias-Perez JF, Maffei B, Maino D, Mandolesi N, Maris M, Martini PG, Martinez-Gonzalez E, Masi S, Matarrese S, Max-Moerbeck W, Meinhold PR, Melchiorri A, Mennella A, Migliaccio M, Millgaliev M, Miville-Deschenes MA, Moneti A, Montier L, Morgante G, Mortlock D, Munshi D, Murphy JA, Nati F, Natoli P, Nieppola E, Noviello F, Novikov D, Novikov I, Pagano L, Pajot F, Paoletti D, Partridge B, Pasian F, Pearson TJ, Perdereau O, Perotto L, Pettorino V, Piacentini F, Piat M, Pierpaoli E, Plaszczynski S, Pointecouteau E, Polenta G, Pratt GW, Ramakrishnan V, Rastorgueva-Foi EA, Readhead ACS, Reinecke M, Remazeilles M, Renault C, Renzi A, Richards JL, Ristorcelli I, Rocha G, Rossetti M, Roudier G, Rubino-Martin JA, Rusholme B, Sandri M, Savelainen M, Savini G, Scott D, Sotnikova Y, Stolyarov V, Sunyaev R, Sutton D, Suur-Uski AS, Sygnet JF, Tammi J, Tauber JA, Terenzi L, Toffolatti L, Tomasi M, Tornikoski M, Tristram M, Tucci M, Turler M, Valenziano L, Valiviita J, Valtaoja E, Van Tent B, Vielva P, Ville F, Wade LA, Wehrle AE, Wehus IK, Yvon D, Zacchei A, Zonca A
Publisher: EDP SCIENCES S A
: 2016
: Astronomy and Astrophysics
: ASTRONOMY & ASTROPHYSICS
: ASTRON ASTROPHYS
: ARTN A106
: 596
: 37
: 1432-0746
DOI: https://doi.org/10.1051/0004-6361/201527780
Continuum spectra covering centimetre to submillimetre wavelengths are presented for a northern sample of 104 extragalactic radio sources, mainly active galactic nuclei, based on four-epoch Planck data. The nine Planck frequencies, from 30 to 857 GHz, are complemented by a set of simultaneous ground-based radio observations between 1.1 and 37 GHz. The single-survey Planck data confirm that the flattest high-frequency radio spectral indices are close to zero, indicating that the original accelerated electron energy spectrum is much harder than commonly thought, with power-law index around 1.5 instead of the canonical 2.5. The radio spectra peak at high frequencies and exhibit a variety of shapes. For a small set of low-z sources, we find a spectral upturn at high frequencies, indicating the presence of intrinsic cold dust. Variability can generally be approximated by achromatic variations, while sources with clear signatures of evolving shocks appear to be limited to the strongest outbursts.
