Ade, PAR;
Aghanim, N;
Aller, HD;
Aller, MF;
Arnaud, M;
Aumont, J;
Baccigalupi, C;
... Zonca, A; + view all
(2016)
Planck intermediate results XLV. Radio spectra of northern extragalactic radio sources.
ASTRONOMY & ASTROPHYSICS
, 596
, Article A106. 10.1051/0004-6361/201527780.
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Abstract
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.
Type: | Article |
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Title: | Planck intermediate results XLV. Radio spectra of northern extragalactic radio sources |
Open access status: | An open access version is available from UCL Discovery |
DOI: | 10.1051/0004-6361/201527780 |
Publisher version: | http://dx.doi.org/10.1051/0004-6361/201527780 |
Additional information: | © ESO, 2016 |
Keywords: | galaxies: active / galaxies: general / radio continuum: galaxies |
UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Space and Climate Physics |
URI: | https://discovery-pp.ucl.ac.uk/id/eprint/1540925 |
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