J/AZh/93/605 AGN long-term variability (Volvach+, 2016)
Long-term variability of active galactic nuclei from the "Planck" catalog.
Volvach A.E., Kardashev N.S., Larionov M.G., Volvach L.N.
<Astron. Zh. 93, 605 (2016)>
=2016AZh....93..605V 2016AZh....93..605V (SIMBAD/NED BibCode)
=2016ARep...60..621V 2016ARep...60..621V
ADC_Keywords: Active gal. nuclei ; Radio sources
Abstract:
Abstract-A complete sample of 104 bright active galactic nuclei
(AGNs) from the "Planck" catalog (early results) were observed at
36.8GHz 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, theMetsahovi 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 1Jy at 36.8GHz.
Description:
Observations with the 13.7-m radio telescope in Metsahovi (Finland)
were carried out at 36.8GHz simultaneously with the PLANCK
observations.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table.dat 81 104 Flux densities and derived spectral indices for data
from Metsahovi (M), the CrAO (C), and WMAP (W)
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See also:
VIII/88 : Planck Early Release Compact Source Catalogue (Planck, 2011)
J/A+A/581/A14 : Updated Planck catalogue PSZ1 (Planck+, 2015)
J/A+A/536/A8 : Planck early results. VIII. ESZ sample. (Planck+, 2011)
Byte-by-byte Description of file: table.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq Sequential number
5- 12 A8 --- BName Source name B1950 (HHMM+DDd)
14- 22 A9 --- JName Source name J2000 (HHMM+DDMM)
25- 38 A14 --- Ident Identification
39 A1 --- n_Ident [*] Note on Ident (1)
41- 45 F5.2 Jy F36.8M Metsahovi flux density at 36.8GHz
47- 51 F5.2 Jy F36.8C CrAO flux density at 36.8GHz
53- 56 F4.2 Jy e_F36.8C rms uncertainty on F36.8C
58- 61 F4.1 Jy F36.8W ? Flux density at 36.8GHz interpolated from
the WMAP data
63- 66 F4.2 Jy e_F36.8W ? Flux density at 36.8GHz
68- 70 I3 % VarM/C Metsahovi/CrAO variability index (2)
72- 76 F5.1 % VarW/C ? WMAP/CrAO variability index (3)
78- 81 F4.1 % e_VarW/C ? rms uncertainty on VarW/C
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Note (1): * for sources promising for observations with the RADIOASTRON
ground-space and the future MILLIMETRON mission.
Note (2): The mean variability indices calculated from the Metsahovi and
CrAO flux densities is 45.
Note (3): The mean variability indices calculated from theWMAP and CrAO flux
densities is 55.7±4.3.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 06-Dec-2016