J/ApJS/260/12 Jet kinematics of blazars at 43GHz with 10yrs obs. (Weaver+, 2022)
Kinematics of parsec-scale jets of gamma-ray blazars at 43GHz during 10yr of
the VLBA-BU-BLAZAR program.
Weaver Z.R., Jorstad S.G., Marscher A.P., Morozova D.A., Troitsky I.S.,
Agudo I., Gomez J.L., Lahteenmaki A., Tammi J., Tornikoski M.
<Astrophys. J. Suppl. Ser., 260, 12 (2022)>
=2022ApJS..260...12W 2022ApJS..260...12W
ADC_Keywords: Active gal. nuclei; BL Lac objects; QSOs; Interferometry;
Radio sources; Gamma rays; Proper motions; Photometry; Optical;
Redshifts
Keywords: Active galaxies ; Relativistic jets ; Interferometry ; Blazars ;
Flat-spectrum radio quasars ; BL Lacertae objects
Abstract:
We analyze the parsec-scale jet kinematics from 2007 June to 2018
December of a sample of γ-ray bright blazars monitored roughly
monthly with the Very Long Baseline Array (VLBA) at 43GHz under the
VLBA-BU-BLAZAR program. We implement a novel piecewise linear fitting
method to derive the kinematics of 521 distinct emission knots from a
total of 3705 total intensity images in 22 quasars, 13 BL Lacertae
objects, and 3 radio galaxies. Apparent speeds of these components
range from 0.01c to 78c, and 18.6% of knots (other than the "core")
are quasi-stationary. One-fifth of moving knots exhibit nonballistic
motion, with acceleration along the jet within 5pc of the core
(projected) and deceleration farther out. These accelerations occur
mainly at locations coincident with quasi-stationary features. We
calculate the physical parameters of 273 knots with statistically
significant motion, including their Doppler factors, Lorentz factors,
and viewing angles. We determine the typical values of these
parameters for each jet and the average for each subclass of active
galactic nuclei. We investigate the variability of the position angle
of each jet over the 10yr of monitoring. The fluctuations in position
of the quasi-stationary components in radio galaxies tend to be
parallel to the jet, while no directional preference is seen in the
components of quasars and BL Lacertae objects. We find a connection
between γ-ray states of blazars and their parsec-scale jet
properties, with blazars with brighter 43GHz cores typically reaching
higher γ-ray maxima during flares.
Description:
As part of the VLBA-BU-BLAZAR monitoring program
(http://www.bu.edu/blazars/BEAM-ME.html), we have obtained roughly
monthly observations with the VLBA at 43GHz (7mm wavelength) of a
sample of AGNs detected as γ-ray sources. The results of the
observations from 2007 June to 2013 January have been presented in
Jorstad+ (2017, J/ApJ/846/98). In this work, we extend the analyzed
period with observations obtained from 2013-January through
2018-December, bringing the total monitoring period to 10.5yr.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 74 38 The VLBA-BU-BLAZAR sample
table2.dat 104 10192 Modeling of jets by Gaussian components 2013-2018
table3.dat 65 559 Jet structure
table8.dat 93 529 Velocity in the jets
table9.dat 56 96 Quasi-stationary jet features
table10.dat 88 104 Acceleration in the jets
table12.dat 81 273 Physical parameters of jet features
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See also:
J/ApJ/430/467 : Extragal. sources superluminal motions (Vermeulen+, 1994)
J/ApJS/123/79 : Third EGRET catalog (3EG) (Hartman+, 1999)
J/ApJ/609/539 : Kinematics of parsec-scale radio jets (Kellermann+, 2004)
J/AJ/130/1418 : AGN jet kinematics (Jorstad+, 2005)
J/A+A/476/L17 : 86 and 43GHz observations of NRAO 150 (Agudo+, 2007)
J/ApJ/706/1253 : MOJAVE VII. Blazar jet acceleration (Homan+, 2009)
J/AJ/138/1874 : MOJAVE. VI. Kinematic analysis of jets (Lister+, 2009)
J/ApJS/188/405 : Fermi-LAT first source catalog (1FGL) (Abdo+, 2010)
J/ApJ/734/43 : X-ray, opt. & radio monitoring of 3C 111 (Chatterjee+, 2011)
J/A+A/535/A69 : AGN Fermi/LAT γ-ray and 37GHz fluxes (Nieppola+, 2011)
J/ApJS/194/29 : Observations of blazars at 15GHz (Richards+, 2011)
J/ApJ/747/63 : 7mm VLBA observations of BL Lac object OJ287 (Agudo+, 2012)
J/A+A/559/A75 : 43GHz observation of the blazar Mrk 421 (Blasi+, 2013)
J/other/RAA/13.259 : γ-ray Doppler factor for Fermi blazars (Fan+, 2013)
J/ApJ/768/40 : R-band & polarimetry of S5 0716+71 (Larionov+, 2013)
J/ApJ/763/L36 : MgII and FeII flux of 3C 454.3 (Leon-Tavares+, 2013)
J/AJ/146/120 : MOJAVE. X. Parsec-scale kinematics of AGNs (Lister+, 2013)
J/other/RAA/14.1135 : Doppler factor for a Fermi blazar sample (Fan+, 2014)
J/MNRAS/441/1899 : Fermi bright blazars (Fuhrmann+, 2014)
J/AJ/148/42 : S4 0954+658 outburst in 2011 March-April (Morozova+, 2014)
J/ApJ/789/135 : Gamma-ray bright blazars spectrophot. (Williamson+, 2014)
J/ApJS/218/23 : Fermi LAT third source catalog (3FGL) (Acero+, 2015)
J/ApJ/813/51 : γ-ray to IR study of CTA 102 (Casadio+, 2015)
J/ApJ/798/134 : MOJAVE. XII. Acceleration of blazar jets (Homan+, 2015)
J/ApJ/804/7 : SaMOSA: optical spectroscopy of Fermi blazars (Isler+, 2015)
J/AJ/152/12 : MOJAVE. XIII. New 15GHz obs. on 1994-2013 (Lister+, 2016)
J/ApJ/826/56 : HST/WFC3 obs. of Cepheids in SN Ia host gal. (Riess+, 2016)
J/A+A/602/A29 : QSO 1308+326 at 15GHz modelfit results (Britzen+, 2017)
J/ApJ/846/98 : Jets of blazars at 43GHz with VLBA (Jorstad+, 2017)
J/MNRAS/467/4565 : Bimodal radio variability in OVRO blazars (Liodakis+, 2017)
J/MNRAS/468/4992 : MOJAVE XIV. AGN jet shapes & angles (Pushkarev+, 2017)
J/ApJS/235/39 : Jet properties of γ-ray-loud 3FGL AGNs (Chen, 2018)
J/ApJ/864/84 : Swift follow-up obs. of TXS 0506+056 blazar (Keivani+, 2018)
J/ApJ/866/137 : Bright blazars var. brightness temp. (Liodakis+, 2018)
J/ApJS/234/12 : MOJAVE XV. VLBA 15GHz obs. of AGN jets (Lister+, 2018)
J/ApJ/874/43 : MOJAVE. XVII. Jet kinematics of AGNs (Lister+, 2019)
J/ApJ/892/105 : 4th cat. of Fermi LAT-detected AGNs (4LAC) (Ajello+, 2020)
J/A+A/649/A153 : BL Lac 86GHz images (Casadio+, 2021)
http://www.bu.edu/blazars/BEAM-ME.html : Large VLBA project BEAM-ME home page
(successor to VLBA-BU-BLAZAR)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Source identifier from its B1950
coordinates
10 A1 --- n_ID Note on ID (1)
12- 22 A11 --- OName Common name
24- 27 A4 --- Type Subclass of blazar (2)
29 A1 --- n_Type Note on Type (1)
31- 36 F6.4 --- z [0.017/2.18] Redshift from NED
38 A1 --- n_z Note on z (1)
40- 44 F5.2 Jy S37avg [0.3/27]? Average total intensity at
37GHz (3)
46- 49 F4.2 Jy e_S37avg [0.1/8]? S37avg uncertainty (3)
51- 56 F6.2 10-8ph/cm2/s SGam [5/207] Average γ-ray photon flux
at 0.1-200GeV (4)
58- 63 F6.2 10-8ph/cm2/s e_SGam [2/338] SGam uncertainty (4)
65- 69 F5.2 mag Rmag [12.4/19.4] Average R-band magnitude (5)
71- 74 F4.2 mag e_Rmag [0.09/1.1] Rmag uncertainty (5)
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Note (1): Note as follows:
a = Source added to the sample in 2009.
b = Redshift has not been confirmed.
c = Source added to the sample in 2010.
d = Source added to the sample in 2012.
e = Classified as a BL object in Jorstad+ (2017, J/ApJ/846/98).
f = Removed from the sample after 2017 July.
g = Source added to the sample in 2014.
h = Source added to the sample in 2017.
Note (2): Type of blazar as follows:
FSRQ = flat-spectrum radio quasar; 22 occurrences
BL = BL Lacertae object; 13 occurrences
RG = radio galaxy; 3 occurrences
Note (3): Average total intensity at 37GHz, <S37>, and its standard deviation
as observed with the Metsahovi Radio Observatory of Aalto University,
Finland, between 2007 January and 2018 December.
Note (4): Average γ-ray photon flux at 0.1-200 GeV, <Sγ>, and
its standard deviation based on the γ-ray light curve of each source,
calculated from the photon and spacecraft data provided by the Fermi
Space Science Center (for details, see Williamson+ 2014, J/ApJ/789/135)
between 2007 January and 2018 December.
Note (5): Average R-band magnitude, <SR> and its standard deviation according
to our observations at the Perkins Telescope between 2007 January and
2018 December.
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Source identifier from its B1950 coordinates
10- 16 F7.3 --- Chi2 [0/406] Chi-square value of Gaussian-component
model
18- 25 F8.3 --- RMS [0.017/1345] Root-mean-square of residuals
from the model
27- 34 F8.3 yr Epoch [2013/2018.94] Epoch of observation start
36- 40 I5 d MJD [56307/58461] Modified Julian Date of
observation start
42- 47 F6.3 Jy S43GHz [0.001/29.41] Flux density at 43 GHz
49- 53 F5.3 Jy e_S43GHz [0.008/1.5] The 1σ uncertainty in S43GHz
55- 59 F5.3 mas R [0/8.61] Distance to the core
61- 65 F5.3 mas e_R [0/3.1] The 1σ uncertainty in R
67- 72 F6.1 deg theta [-180/180] Relative position angle with
respect to core
74- 77 F4.1 deg e_theta [0/69] The 1σ uncertainty in theta
79- 83 F5.3 mas a [0.02/3.1] Angular size (1)
85- 89 F5.3 mas e_a [0.003/0.17] The 1σ uncertainty in a
91- 98 F8.1 K Tb [0/172415] Observed brightness temperature (2)
100- 104 A5 --- f_Tb Boolean flag on Tb (3)
--------------------------------------------------------------------------------
Note (1): Corresponding to the FWHM of the circular Gaussian component.
Note (2): Where Tb=7.5e8S/a2.K
Note (3): "True" Indicates a lower limit on Tb. See Section 2.1 for details.
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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 name from its B1950 coordinates
10- 13 A4 --- Knot Knot designation
15- 17 I3 --- N [3/133] Number of epochs the knot was detected
19- 22 F4.2 Jy S43avg [0.01/6.8] Mean 43GHz flux density (1)
24- 27 F4.2 Jy e_S43avg [0/6.7] Standard deviation in S43avg
29- 32 F4.2 mas Ravg [0/7.14] Mean distance (2)
34- 37 F4.2 mas e_Ravg [0.01/2.1] Standard deviation in Ravg
39- 44 F6.1 deg theta [-178/180] Mean position angle for the knot (3)
46- 50 F5.1 deg e_theta [0/156] Standard deviation in theta
52- 55 F4.2 mas aavg [0.02/1.4] Mean knot size (1)
57- 60 F4.2 mas e_aavg [0/0.7] Standard deviation in aavg
62- 65 A4 --- Type Knot type (4)
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Note (1): Of the knot over the epochs when it was detected.
Note (2): Of the knot over the epochs when it was detected. This represents
the typical distance at which a knot was observed, although it is
not necessarily the mid-point of its trajectory.
Note (3): Of the knot over the epochs when it was detected, except the core.
In the case of the core it is the average projected direction of
the inner jet. The direction of the inner jet for the source
0235+164 is uncertain, since features detected in the jet have a
range of P.A. exceeding 180 degrees. The value of 0 given for the
A0 component (core) of this source is a placeholder for no value.
Note (4): Type as follows:
Core = Core component; 38 occurrences
St = quasi-stationary; 96 occurrences
M = moving feature; 425 occurrences
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Byte-by-byte Description of file: table8.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Source identifier from its B1950 coordinates
10- 13 A4 --- Knot Knot designation
15 I1 --- N [1/5] Segment number of piecewise linear fit
17- 25 F9.4 yr Start [2004.5/2018.7] Start epoch of linear
segment (1)
27- 35 F9.4 yr End [2005.3/2018.94] End epoch of linear segment (1)
37- 41 F5.3 mas/yr mu [0.006/5.3] Proper motion
43- 47 F5.3 mas/yr e_mu [0.001/0.3] Uncertainty in mu
49- 54 F6.1 deg Phi [-178.5/179.7] Direction of motion
56- 60 F5.1 deg e_Phi [0.1/240.2] Uncertainty in Phi
62- 66 F5.2 --- beta [0.01/78.7] Apparent speed
68- 72 F5.2 --- e_beta [0.02/11.3] Uncertainty in beta
74- 82 F9.4 yr Tcirc [1977.3/2018.5]? Epoch of Ejection (2)
84- 90 F7.4 yr e_Tcirc [0.0029/61.5]? Uncertainty in Tcirc (2)
92- 93 A2 --- f_Tcirc Flag for Epoch of Ejection
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Note (1): Knots with a single motion segment have no error in their start and
end times as these are the first and last observation of the knot,
respectively. The typical error on the segment start and end times
for knots fit with multiple segments is σT{~<}0.01yr and
are determined from the covariance matrices of fit parameters in the
least-squares piece-wise linear fitting.
Note (2): Epoch of ejection determined for the first linear segment for each
knot, otherwise NA. Calculated from fit to the X and Y relative motion
or motion along R, depending on the value of f_Tcirc
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Source name from its B1950 coordinates
10- 12 A3 --- Knot Knot designation
14- 16 I3 --- N [3/132] Number of epochs stationary feature
observed
18- 22 F5.2 pc R [0.08/37.41] Projected linear distance (1)
24- 27 F4.2 pc e_R [0.01/2.23] Uncertainty in R
29- 33 F5.2 mas X [-1.92/4.49] Mean position of the knot (2)
35- 39 F5.2 mas Y [-3.05/0.99] Mean position of the knot (2)
41- 44 F4.2 mas A [0.03/0.96] Semimajor axis length
46- 49 F4.2 mas B [0.01/0.57] Semiminor axis length
51- 56 F6.1 deg varpi [-133.8/42.6] Orientation angle of
semimajor axis relative to north
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Note (1): From the core to the mean position of the knot.
Note (2): Along the (X|Y) (relative RA|Dec) axis.
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Byte-by-byte Description of file: table10.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- ID Source identifier from its B1950 coordinates
10- 12 A3 --- Knot Knot designation
14 I1 --- Reg [1/4] Acceleration region number
16- 22 F7.2 yr Start [2006.66/2018.15] Start epoch of
acceleration region (1)
24- 30 F7.2 yr End [2008.16/2018.74] End epoch of
acceleration region (1)
32- 37 F6.3 mas/yr2 dotmu-II [-2.25/1.6] Acceleration parallel (2)
39- 43 F5.3 mas/yr2 e_dotmu-II [0.001/0.8] Uncertainty in dotmu-II
45- 50 F6.3 mas/yr2 dotmu-pp [-0.98/2.25] Acceleration perpendicular (2)
52- 56 F5.3 mas/yr2 e_dotmu-pp [0.001/0.32] Uncertainty in dotmu-pp
58- 61 F4.2 pc Rdotmu [0.14/6.15] Distance from the core
to the acceleration region
63- 68 F6.3 yr-1 eta-II [-3.9/17.7] Normalized acceleration
parallel (2)
70- 75 F6.3 yr-1 e_eta-II [0.006/11.95] Uncertainty in eta-II
77- 82 F6.3 yr-1 eta-pp [-8.013/6.81] Normalized acceleration
perpendicular (2)
84- 88 F5.3 yr-1 e_eta-pp [0.008/7.1] Uncertainty in eta-pp
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Note (1): Typical uncertainties in the estimated start and end epoch of
the acceleration region are <0.01yr. The uncertainties in the
acceleration are dominated by the uncertainty in the speeds rather
than the time period of acceleration.
Note (2): To the jet axis.
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Byte-by-byte Description of file: table12.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- ID Source name from its B1950 coordinates
10- 12 A3 --- Knot Knot designation
14- 18 F5.3 yr tau [0.1/9.8] Timescale of variability, τvar
20- 24 F5.3 yr e_tau [0.01/3] Uncertainty in tau
26- 30 F5.3 mas aavg [0.05/1.6] Mean knot size,
32- 36 F5.3 mas e_aavg [0.002/0.06] Uncertainty in Size
38- 39 I2 --- Nt [3/81] Number of epochs (1)
41- 47 F7.3 --- delta [1.5/103.9] Doppler factor of variability
49- 54 F6.3 --- e_delta [0.1/37.8] Uncertainty in delta
56- 62 F7.3 --- Gamma [1.7/132.2] Lorentz factor
64- 69 F6.3 --- e_Gamma [0.036/24] Uncertainty in Gamma
71- 75 F5.2 deg theta [0.14/30.2] Viewing angle, Θ○
77- 81 F5.2 deg e_theta [0.03/15.6] Uncertainty in theta
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Note (1): Used to calculate physical parameters.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 20-Jul-2022