J/MNRAS/520/6053 MOJAVE. Persistent polarization in AGN jets (Pushkarev+ 2023)
MOJAVE. XX. Persistent linear polarization structure in parsec-scale AGN jets
Pushkarev A.B., Aller H.D., Aller M.F., Homan D.C, Kovalev Y.Y.,
Lister M.L., Pashchenko I.N., Savolainen T., Zobnina, D.I.
<Mon. Not. R. Astron. Soc. 520, 6053-6069 (2023)>
=2023MNRAS.520.6053P 2023MNRAS.520.6053P (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio ; Interferometry ; VLBI
Keywords: polarization - galaxies: active - BL Lacertae objects: general -
galaxies: jets - quasars: general - radio continuum: galaxies
Abstract:
We analysed the parsec-scale linear polarization properties of 436
active galactic nuclei (AGN) based on 15GHz polarimetric Very Long
Baseline Array (VLBA) observations. We present polarization and total
intensity images averaged over at least five epochs since 1996 January
19 through 2019 August 4. Stacking improves the image sensitivity down
to ∼30uJy/beam and effectively fills out the jet cross-section
both in total intensity and linear polarization. It delineates the
long-term persistent magnetic field configuration and its regularity
by restoring spatial distributions of the electric vector position
angle (EVPA) and fractional polarization, respectively. On average,
about ten years of stacking period is needed to reveal the stable and
most-complete polarization distribution of a source. We find that the
degree of polarization significantly increases down and across the jet
towards its edges, typically manifesting U or W-shaped transverse
profiles, suggesting a presence of a large-scale helical magnetic
field associated with the outflow. In some AGN jets, mainly BL Lacs,
we detect quasi-constant fractional polarization profiles across the
jet, accompanied by EVPAs that closely follow the outflow. BL Lacs
show higher fractional polarization values in their cores and jets
than those in quasars up to hectoparsec de-projected scales, while on
larger scales, they become comparable. High-synchrotron-peaked BL Lac
jets are found to be less polarized than intermediate and
low-synchrotron-peaked BL Lacs. The spatial distribution of the EVPAs
in BL Lacs tend to align with the local jet direction, while quasars
show an excess of orthogonal polarization orientation.
Description:
File table1 contains the name of the sources in B1950 and J2000
notations, alias, redshift, optical class, MOJAVE 1.5Jy sample
membership flag, Fermi-LAT detection flag, SED class, reference for
redshift/optical class, reference for SED classification.
File table2 contains the name of of a source in the B1950 notation,
date of first epoch of VLBA observations, time span between first and
last epochs, number of observing epochs, size of the restoring beam,
map peak in total intensity, map peak in linear polarization, noise
level of total intensity map, noise level of linear polarization map.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 114 436 Source properties
table2.dat 69 436 Summary of 15 GHz stacked map parameters
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See also:
J/AJ/137/3718 : 15GHz monitoring of AGN jets with VLBA (Lister+, 2009)
J/ApJS/171/376 : MOJAVE. III. VLA 1.4GHz images (Cooper+, 2007)
J/AJ/131/1262 : Circular polarization images at 15GHz of AGN jets
(Homan+, 2006)
J/AJ/130/1389 : Linear polarization of AGN jets at 15GHz (Lister+, 2005)
J/AJ/138/1874 : MOJAVE. VI. Kinematic analysis of blazar jets
(Lister+, 2009)
J/ApJ/706/1253 : MOJAVE VII. Blazar jet acceleration (Homan+, 2009)
J/AJ/144/105 : MOJAVE. VIII. Faraday rotation in AGN jets. (Hovatta+, 2012)
J/A+A/545/A113 : MOJAVE IX. Core shift effects (Pushkarev+, 2012)
J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)
J/AJ/147/143 : MOJAVE. XI. Spectral distributions (Hovatta+, 2014)
J/ApJ/798/134 : MOJAVE. XII. Acceleration of blazar jets (Homan+, 2015)
J/AJ/152/12 : MOJAVE. XIII. New 15GHz observations on 1994-2013
(Lister+, 2016)
J/MNRAS/468/4992 : MOJAVE XIV. AGN jet shapes + opening angles
(Pushkarev+, 2017)
J/ApJS/234/12 : MOJAVE XV. VLBA 15GHz obs. of AGN jets 1996-2016
(Lister+, 2018)
J/ApJ/862/151 : MOJAVE. XVI: parsec-scale AGN jet cores at 15GHz
(Hodge+, 2018)
J/ApJ/874/43 : MOJAVE. XVII. Parsec-scale jet kinematics of AGNs
(Lister+, 2019)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- NameB1950 Source name (B1950)
11- 20 A10 --- NameJ2000 Source name (J2000)
23- 42 A20 --- Alias Other name
45- 52 F8.6 --- z ? Redshift
55 A1 --- OptClass [BGNQU] Optical class
58 A1 --- Flag1.5Jy [Y/N] MOJAVE 1.5 Jy sample membership flag
61 A1 --- LAT [Y/N] Fermi LAT detected
64- 66 A3 --- SED SED class
69- 94 A26 --- r_z Reference for redshift / optical class (1)
96-114 A19 --- r_SED Reference for SED classification
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Note (1): Foschini2022 : 2022Univ....8..587F 2022Univ....8..587F, Cat. J/other/Univ/8.587
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Byte-by-byte Description of file: table2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- NameB1950 Source name (B1950)
11- 20 A10 "date" Date Date of first epoch
23- 27 F5.2 yr tau Time range between first and last epochs
30- 32 I3 --- N Number of stacked epochs
36- 39 F4.2 mas Beam FWHM of circular restoring beam
42- 48 F7.1 mJy/beam Ipeak Total intensity peak of image at 15GHz
51- 55 F5.1 mJy/beam Ppeak Polarized intensity peak of image at 15GHz
59- 62 F4.2 mJy/beam Irms rms noise level of I-image at 15GHz
66- 69 F4.2 mJy/beam Prms rms noise level of P-image at 15GHz
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Acknowledgements:
Alexander Pushkarev, pushkarev.alexander(at)gmail.com
References:
Lister et al. Paper I 2005AJ....130.1389L 2005AJ....130.1389L, Cat. J/AJ/130/1389
Homan et al. Paper II 2006AJ....131.1262H 2006AJ....131.1262H, Cat. J/AJ/131/1262
Cooper et al. Paper III 2007ApJS..171..376C 2007ApJS..171..376C, Cat. J/ApJS/171/376
Cara & Lister Paper IV 2008ApJ...674..111C 2008ApJ...674..111C
Lister et al. Paper V 2009AJ....137.3718L 2009AJ....137.3718L, Cat. J/AJ/137/3718
Lister et al. Paper VI 2009AJ....138.1874L 2009AJ....138.1874L, Cat. J/AJ/138/1874
Homan et al. Paper VII 2009ApJ...706.1253H 2009ApJ...706.1253H, Cat. J/ApJ/706/1253
Hovatta et al. Paper VIII 2012AJ....144..105H 2012AJ....144..105H, Cat. J/AJ/144/105
Pushkarev et al. Paper IX 2012A&A...545A.113P 2012A&A...545A.113P, Cat. J/A+A/545/A113
Lister et al. Paper X 2013AJ....146..120L 2013AJ....146..120L, Cat. J/AJ/146/120
Hovatta et al. Paper XI 2014AJ....147..143H 2014AJ....147..143H, Cat. J/AJ/147/143
Homan et al. Paper XII 2015ApJ...798..134H 2015ApJ...798..134H, cat. J/ApJ/798/134
Lister et al. Paper XIII 2016AJ....152...12L 2016AJ....152...12L, Cat. J/AJ/152/12
Pushkarev et al. Paper XIV 2017MNRAS.468.4992P 2017MNRAS.468.4992P, Cat. J/MNRAS/468/4992
Lister et al. Paper XV 2018ApJS..234...12L 2018ApJS..234...12L, Cat. J/ApJS/234/12
Hodge et al. Paper XVI 2018ApJ...862..151H 2018ApJ...862..151H, Cat. J/ApJ/862/151
Lister et al. Paper XVII 2019ApJ...874...43L 2019ApJ...874...43L, Cat. J/ApJ/874/43
Homan et al. Paper XIX 2021ApJ...923...67H 2021ApJ...923...67H
(End) Alexander Pushkarev [CrAO, Russia], Patricia Vannier [CDS] 07-Mar-2023