J/ApJ/862/151 MOJAVE. XVI: parsec-scale AGN jet cores at 15GHz (Hodge+, 2018)
MOJAVE.
XVI: multiepoch linear polarization properties of parsec-scale AGN jet cores.
Hodge M.A., Lister M.L., Aller M.F., Aller H.D., Kovalev Y.Y.,
Pushkarev A.B., Savolainen T.
<Astrophys. J., 862, 151 (2018)>
=2018ApJ...862..151H 2018ApJ...862..151H
ADC_Keywords: Active gal. nuclei; Polarization; Radio continuum; Redshifts
Keywords: BL Lacertae objects: general ; galaxies: active ; galaxies: jets ;
polarization ; quasars: general ; radio continuum: galaxies
Abstract:
We present an analysis of the core linear polarization properties of
387 parsec-scale active galactic nuclei (AGNs) jets. Using 15GHz VLBA
data, we revisit the conclusions of the first paper in this series
with multiepoch measurements and more detailed analysis of a larger
AGN sample that spans a broader range of synchrotron peak frequencies.
Each AGN has been observed for at least five epochs between 1996 and
2017. We find that BL Lac objects have core electric vector position
angles (EVPAs) that tend toward alignment with the local jet
direction; compared to flat spectrum radio quasars, their EVPAs are
also less variable over time. The AGN cores that are most fractionally
polarized and least variable in polarization have EVPAs that are
closely aligned with the local jet direction; they also have low
variability in EVPA. These results support the popular model of a
standing transverse shock at the base of the jet that collimates the
jet magnetic field perpendicular to the jet direction, increasing the
fractional polarization and leading to greater polarization stability
over time. High-synchrotron-peaked BL Lac objects form a low
luminosity, low fractional polarization population. The five narrow
line Seyfert 1 galaxies in our sample have low fractional polarization
and large EVPA-jet misalignments. Although AGNs detected at
γ-rays are thought to be more Doppler boosted than nondetected
AGNs, we find no significant differences in fractional polarization
based on detection by Fermi-LAT; the γ-loud AGNs are, however,
more variable in core EVPAs.
Description:
In this paper, we analyze the parsec-scale radio core polarization and
total intensity properties of 387 AGNs selected from the MOJAVE survey
that have at least five VLBA epochs at 15GHz between 1996 January 19
and 2016 December 31.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 76 387 General properties of the AGN sample
table3.dat 45 5153 VLBA 15GHz core measurements
table4.dat 44 387 Derived core quantities
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See also:
VII/249 : 6dF-DR2 Galaxy Survey (Jones+, 2005)
J/AJ/109/1498 : Large Bright Quasar Survey VI (LBQS) (Hewett+, 1995)
J/ApJS/123/79 : Third EGRET catalog (3EG) (Hartman+, 1999)
J/ApJS/121/287 : The CfA2S catalog (Huchra+, 1999)
J/ApJ/589/733 : VLBI polarimetry of CJF sources (Pollack+, 2003)
J/AJ/130/1389 : Linear polarization of AGN jets at 15GHz (Lister+, 2005)
J/ApJ/626/95 : Gamma-ray blazar candidates (Sowards-Emmerd+, 2005)
J/A+A/476/L17 : 86 and 43GHz observations of NRAO 150 (Agudo+, 2007)
J/ApJ/658/203 : VLBA imaging & polarimetry survey at 5GHz (Helmboldt+, 2007)
J/AJ/134/799 : Multiwaveband polarimetry of 15 AGN (Jorstad+, 2007)
J/ApJ/700/597 : FERMI LAT detected blazars (Abdo+, 2009)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJ/743/171 : The 2LAC catalog (Ackermann+, 2011)
J/ApJ/742/27 : 15GHz and jet properties of MOJAVE blazars (Lister+, 2011)
J/AJ/144/105 : MOJAVE. VIII. Faraday rotation in AGN jets. (Hovatta+, 2012)
J/ApJ/744/177 : VLBA 5GHz observations of Fermi/LAT AGNs (Linford+, 2012)
J/ApJ/757/25 : Fermi/LAT AGN at 5GHz (Linford+, 2012)
J/ApJ/748/49 : Opt. spectroscopy of 1LAC broad-line blazars (Shaw+, 2012)
J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)
J/ApJ/764/135 : Spectroscopic redshifts of BL Lac objects (Shaw+, 2013)
J/A+A/566/A59 : 3.5 & 1.3mm polarim. survey of Northern AGNs (Agudo+, 2014)
J/MNRAS/442/1693 : Gamma-ray-loud blazars opt. polarization (Pavlidou+, 2014)
J/MNRAS/438/3058 : 15GHz variability of γ-ray blazars (Richards+, 2014)
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/ApJ/810/14 : Third catalog of LAT-detected AGNs (3LAC) (Ackermann+, 2015)
J/AJ/152/12 : MOJAVE. XIII. New 15GHz obs. on 1994-2013 (Lister+, 2016)
J/ApJ/846/98 : Blazar jet kinematics at 43GHz with VLBA (Jorstad+, 2017)
J/ApJS/234/12 : MOJAVE XV. VLBA 15GHz obs. 1996-2016 (Lister+, 2018)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Source identifier (HHMM+DDd; B1950)
10- 30 A21 --- Alias Source alias (1)
32 A1 --- 1.5Jy MOJAVE 1.5Jy catalog inclusion? (2)
34 A1 --- LAT Status of Fermi/LAT detection (2)
36 I1 --- f_LAT [1]? Flag on LAT (3)
38 A1 --- OClass Optical class (4)
40- 42 A3 --- PClass Class based on synchrotron peak frequency (5)
44- 47 F4.1 [Hz] log(nuP) [12/17.1]? log rest frame peak synchrotron
frequency (6)
49- 56 F8.6 --- z [0.004/3.4]? Spectroscopic redshift
58- 76 A19 --- r_z Bibcode reference for z (7)
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Note (1): OC -010 for ID 0605-085 is very likely a misprint for OH -010;
corrected at CDS.
Note (2): (Y)es or (N)o.
Note (3):
1 = Located within 10 degrees of the galactic plane;
omitted from γ-ray comparisons.
Note (4): Class as follows:
Q = FSRQ (239 occurrences);
B = BL Lac (118 occurrences);
G = radio galaxy (17 occurrences);
N = narrow line Seyfert 1 (5 occurrences);
U = unidentified (8 occurrences).
Note (5): Class as follows:
LSP = low-synchrotron-peaked (νp below 1014Hz);
ISP = intermediate-synchrotron-peaked (νp between 1014Hz and 1015Hz);
HSP = high-synchrotron-peaked (νp above 1015Hz).
Note (6): For sources with no known redshift, z=0.3 was used.
Note (7): or optical class, for BL Lacs without known redshift.
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Source identifier (HHMM+DDd; B1950)
10- 19 A10 "Y/M/D" Date UT date of the observation
21- 25 F5.2 Jy/beam I [0.01/26.5] Stokes I intensity
27 A1 --- l_m Limit flag on m
29- 33 F5.2 % m [0.03/14.3] Fractional polarization
35- 39 F5.1 deg EVPA [-81/270]? Electric vector position angle
41- 43 I3 deg JetPA [0/360] Inner jet position angle (1)
45 A1 --- f_JetPA [a] Flag on JetPA (2)
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Note (1): Unless otherwise noted, measured as the position angle of the
closest downstream Gaussian jet component with respect to the core.
Note (2):
a = PA measurement method: Flux-weighted position angle average of
clean components near the core.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Source identifier (HHMM+DDd; B1950)
10- 13 F4.1 % mMed [0.2/11.6]? Median fractional polarization
15 A1 --- l_mMax Limit flag on mMax
16- 19 F4.1 % mMax [0.1/14.3]? Maximum fractional polarization
21- 24 F4.2 --- mVar [0/1]? Fractional polarization variability
26- 30 F5.2 Jy/beam IMed [0.02/10.5] Median total Stokes I intensity
32- 35 F4.2 --- IVar [0/0.7]? Total intensity variability
37- 38 I2 deg EVPA [2/57]? Electric vector position angle
variability
40- 41 I2 deg VarPA [2/58]? EVPA variability relative to jet PA
43- 44 I2 deg DiffPA [2/87]? Median difference between EVPA and JetPA
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History:
From electronic version of the journal
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
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Lister et al. Paper VI. 2009AJ....138.1874L 2009AJ....138.1874L Cat. J/AJ/138/1874
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Pushkarev et al. Paper IX. 2012A&A...545A.113P 2012A&A...545A.113P Cat. J/A+A/545/A113
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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 This catalog
Lister et al. Paper XVII. 2019ApJ...874...43L 2019ApJ...874...43L Cat. J/ApJ/874/43
Lister et al. Paper XVIII. 2021ApJ...923...30L 2021ApJ...923...30L Cat. J/ApJ/923/30
Homan et al. Paper XIX. 2021ApJ...923...67H 2021ApJ...923...67H Cat. J/ApJ/923/67
Pushkarev et al. Paper XX. 2023MNRAS.520.6053P 2023MNRAS.520.6053P
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 31-Jul-2019