J/MNRAS/493/L54 Optical polarization properties of AGNs (Kovalev+, 2020)
Optical polarization properties of AGNs with significant VLBI-Gaia offsets.
Kovalev Y.Y., Zobnina D.I., Plavin A.V., Blinov D.
<Mon. Not. R. Astron. Soc. 493, L54 (2020)>
=2020MNRAS.493L..54K 2020MNRAS.493L..54K (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Polarization
Keywords: polarization - astrometry - galaxies: active - galaxies: jets -
radio continuum: galaxies - galaxies: disc
Abstract:
Significant positional offsets of the value from 1 mas to more than
10mas were found previously between radio (VLBI) and optical (Gaia)
positions of active galactic nuclei (AGNs). They happen preferentially
parallel to the parsec-scale jet direction. AGNs with VLBI-to-Gaia
offsets pointed downstream the jet are found to have favourably higher
optical polarization, as expected if extended optical jets dominate in
the emission and shift the Gaia centroid away from the physical
nucleus of the source. Upstream offsets with the suggested domination
of accretion discs manifest themselves through the observed low
optical polarization. Direction of linear optical polarization is
confirmed to preferentially align with parsec-scale jets in AGNs with
dominant jets consistent with a toroidal magnetic field structure. Our
findings support the disc-jet interpretation of the observed
positional offsets. These results call on an intensification of AGN
optical polarization monitoring programs in order to collect precious
observational data. Taken together with the continued VLBI and Gaia
observations, they will allow researchers to reconstruct detailed
models of the disc-jet system in AGNs on parsec scales.
Description:
Data with results of VLBI, Gaia, and optical polarization measurements.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 121 1059 Properties of 1059 AGN with significant
VLBI-Gaia offsets
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See also:
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 I19 --- GaiaDR2 ID in Gaia DR2
21- 22 I2 h RAh Gaia DR2 right ascension (J2000)
24- 25 I2 min RAm Gaia DR2 right ascension (J2000)
27- 32 F6.3 s RAd Gaia DR2 right ascension (J2000)
34 A1 --- DE- Gaia DR2 declination sign (J2000)
35- 36 I2 deg DEd Gaia DR2 declination (J2000)
38- 39 I2 arcmin DEm Gaia DR2 declination (J2000)
41- 46 F6.3 arcsec DEs Gaia DR2 declination (J2000)
48- 53 F6.3 mag RPmag ? RP-magnitude in Gaia DR2
55- 60 F6.3 mag Gmag G-magnitude in Gaia DR2
62- 67 F6.3 mag BPmag ? BP-magnitude in Gaia DR2
69- 78 A10 --- J2000 J2000 name from RFC
80- 85 F6.1 deg PAj VLBI jet position angle
87- 94 F8.3 mas offset Offset between VLBI and Gaia positions
96-101 F6.1 deg psi VLBI-Gaia offset direction relative to jet
103-106 F4.1 deg s_psi Standard deviation of VLBI-Gaia offset direction
108-112 F5.3 --- Polfrac ? Optical polarization fraction
114-118 F5.1 deg PolPA ? Optical polarization position angle
120-121 A2 --- Band [R V WL] Optical polarization measurement band
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Acknowledgements:
Alexander Kovalev, alexander(at)plav.in
(End) Patricia Vannier [CDS] 17-Jan-2020