Long-term variability of active galactic nuclei from the ”Planck” catalog

A complete sample of 104 bright active galactic nuclei (AGNs) from the “Planck” catalog (early results) were observed at 36.8 GHz with the 22-m radio telescope of the Crimean Astrophysical Observatory (CrAO).Variability indices of the sources at this frequency were determined based on data from theW...

Full description

Saved in:
Bibliographic Details
Published in:Astronomy reports 2016-07, Vol.60 (7), p.621-629
Main Authors: Volvach, A. E., Kardashev, N. S., Larionov, M. G., Volvach, L. N.
Format: Article
Language:English
Subjects:
Active galactic nuclei
Astronomy
Coalescence
Coalescing
Fluctuations
Flux
Flux density
Infrared
Observations and Techniques
Observatories
Physics
Physics and Astronomy
Radio
Radio sources (astronomy)
Radio telescopes
Variability
Wavelengths
Citations: Items that this one cites
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A complete sample of 104 bright active galactic nuclei (AGNs) from the “Planck” catalog (early results) were observed at 36.8 GHz with the 22-m radio telescope of the Crimean Astrophysical Observatory (CrAO).Variability indices of the sources at this frequency were determined based on data from theWMAP space observatory, theMetsa¨ hovi RadioObservatory (Finland), and the CrimeanAstrophysical Observatory. New observational results confirm that the variability of these AGNs is stronger in the millimeter than at other radio wavelengths. The variability indices probably change as a result of the systematic decrease in the AGN flux densities in the transition to the infrared. Some radio sources demonstrate significant flux-density variations, including decreases, which sometimes cause them to fall out of the analysed sample. The change of the variability index in the millimeter is consistent with the suggestion that this variability is due to intrinsic processes in binary supermassive black holes at an evolutionary stage close to coalescence. All 104 of the sources studied are well known objects that are included in various radio catalogs and have flux densities exceeding 1 Jy at 36.8 GHz.
ISSN:1063-7729
1562-6881
DOI:10.1134/S106377291607009X