Next Article in Journal / Special Issue
Through the Looking Glass: Faraday Conversion in Turbulent Blazar Jets
Previous Article in Journal / Special Issue
Millimeter VLBI of NGC 1052: Dynamics
Article Menu

Export Article

Open AccessReview
Galaxies 2016, 4(4), 49;

Multifrequency Studies of Active Galactic Nuclei in the Planck Satellite Era

Aalto University Metsähovi Radio Observatory & Department of Radio Science and Engineering, P.O. Box 13000, FI-00076 AALTO, Finland
Author to whom correspondence should be addressed.
Academic Editors: Jose L. Gómez, Alan P. Marscher and Svetlana G. Jorstad
Received: 5 July 2016 / Revised: 18 October 2016 / Accepted: 19 October 2016 / Published: 21 October 2016
(This article belongs to the Special Issue Blazars through Sharp Multi-wavelength Eyes)
Full-Text   |   PDF [216 KB, uploaded 21 October 2016]


The multi-epoch single-survey Planck satellite data have given a rare glimpse into how the radio spectra of active galactic nuclei (AGN) evolve in time. Using Planck and simultaneous auxiliary radio data ranging from 1 GHz to 857 GHz, spectra for 104 bright northern extragalactic radio sources (most of them AGN) have been assembled; in these, the various stages of flare development can be identified. The results are compared with theoretical models describing relativistic jets. Evidence for particularly flat high-frequency radio spectra is found, indicating a harder accelerated electron energy spectrum than usually assumed. A set of sources also shows signs of intrinsic cold dust. View Full-Text
Keywords: active galactic nuclei; radio spectra; relativistic jets active galactic nuclei; radio spectra; relativistic jets
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).

Share & Cite This Article

MDPI and ACS Style

Lähteenmäki, A.; the Planck Collaboration. Multifrequency Studies of Active Galactic Nuclei in the Planck Satellite Era. Galaxies 2016, 4, 49.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics



[Return to top]
Galaxies EISSN 2075-4434 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top