J/A+A/651/A74 4C +29.45 OVRO and KNV fluxes curve (Kang+, 2021)
Interferometric monitoring of gamma-ray bright AGNs:
Measuring the magnetic field strength of 4C +29.45.
Kang S., Lee S.-S., Hodgson J., Algaba J.-C., Lee J. W., Kim J.-Y.,
Park J., Kino M., Kim D., Trippe S.
<Astron. Astrophys. 651, A74 (2021)>
=2021A&A...651A..74K 2021A&A...651A..74K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; Radio continuum ; VLBI
Keywords: galaxies: active - galaxies: jets -
BL Lacertae objects: individual: J1159+2914
Abstract:
We present the results of multi-epoch, multifrequency monitoring of
blazar 4C +29.45, which was regularly monitored as part of the
Interferometric Monitoring of GAmma-ray Bright Active Galactic Nuclei
(iMOGABA) program - a key science program of the Korean Very long
baseline interferometry Network (KVN). Observations were conducted
simultaneously at 22, 43, 86, and 129GHz over the 4 years from 5
December 2012 to 28 December 2016. We also used additional data from
the 15GHz Owens Valley Radio Observatory (OVRO) monitoring program.
From the 15GHz light curve, we estimated the variability timescales
of the source during several radio flux enhancements. We found that
the source experienced six radio flux enhancements with variability
timescales of 9-187days during the observing period, yielding
corresponding variability Doppler factors of 9-27. From the
simultaneous multifrequency KVN observations, we were able to obtain
accurate radio spectra of the source and hence to more precisely
measure the turnover frequencies νr, of synchrotron
self-absorption (SSA) emission with a mean value of νr=28.9GHz.
Using jet geometry assumptions, we estimated the size of the emitting
region at the turnover frequency. We found that the equipartition
magnetic field strength is up to two orders of magnitude higher than
the SSA magnetic field strength (0.001-0.1G). This is consistent with
the source being particle dominated. We performed a careful analysis
of the systematic errors related to the making of these estimations.
From the results, we concluded that the equipartition region is
located upstream from the SSA region.
Description:
We present the results of multi-epoch, multifrequency monitoring of
blazar 4C +29.45. The data obtained from KVN (22, 43, 86, and 129GHz)
and OVRO (15GHz).
Objects:
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RA (2000) DE Designation(s)
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11 59 31.83 +29 14 43.8 4C +29.45 = CGRaBS J1159+2914
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
subp1.dat 48 211 OVRO 15GHz data
subp2.dat 19 33 KVN 22GHz data
subp3.dat 19 29 KVN 43GHz data
subp4.dat 19 26 KVN 86GHz data
subp5.dat 19 17 KVN 129GHz data
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Byte-by-byte Description of file: subp1.dat
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Bytes Format Units Label Explanations
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1- 13 F13.7 d MJD Modified Julian date
15- 16 I2 GHz Freq [15] Frequency
18- 31 F14.12 Jy S Flux density
33- 48 F16.14 Jy e_S Error on flux density
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Byte-by-byte Description of file: subp2.dat subp3.dat subp4.dat subp5.dat
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Bytes Format Units Label Explanations
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1- 5 I5 d MJD Modified Julian date
7- 9 I3 GHz Freq Frequency (22 43 86 129)
11- 14 F4.2 Jy S Flux density
16- 19 F4.2 Jy e_S Error on flux density
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Acknowledgements:
Sincheol Kang, kang87(at)kasi.re.kr
Sang-Sung Lee, sslee(at)kasi.re.kr
(End) Patricia Vannier [CDS] 19-May-2021