J/A+A/545/A113 MOJAVE IX. Core shift effects (Pushkarev+, 2012)
MOJAVE: Monitoring of jets in active galactic nuclei with VLBA experiments.
IX. Nuclear opacity.
Pushkarev A.B., Hovatta T., Kovalev Y.Y., Lister M.L., Lobanov A.P.,
Savolainen T., Zensus J.A.
<Astron. Astrophys., 545, A113 (2012)>
=2012A&A...545A.113P 2012A&A...545A.113P
ADC_Keywords: Active gal. nuclei ; QSOs ; Magnetic fields
Keywords: galaxies: active - galaxies: jets - radio continuum: galaxies -
quasars: general
Abstract:
We have investigated a frequency-dependent shift in the absolute
position of the optically thick apparent origin of parsec-scale jets
("core shift" effect) to probe physical conditions in
ultra-compact relativistic outflows in active galactic nuclei.
We used multi-frequency Very Long Baseline Array (VLBA) observations
of 191 sources carried out in 12 epochs in 2006 within the Monitoring
Of Jets in Active galactic nuclei with VLBA Experiments (MOJAVE)
program. The observations were performed at 8.1, 8.4, 12.1, and
15.4GHz. We implemented a method of determining the core shift vector
based on (i) image registration by two-dimensional normalized
cross-correlation and (ii) model-fitting the source brightness
distribution to take into account a non-zero core component offset
from the phase center.
Description:
The MOJAVE project is a long-term VLBA program aimed at investigating
the structure and evolution of extragalactic relativistic radio jets
in the northern sky. The full monitoring list currently consists of
about 300 sources, and includes a statistically complete, flux-density
limited sample of 135 AGN, referred to as MOJAVE-1. In addition to the
program's usual single-frequency setup at 15.4GHz, 12 monthly
separated epochs of observations during 2006 were carried out
simultaneously also at 12.1, 8.4, and 8.1GHz.
File Summary:
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FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 86 174 Derived core shift vectors
table4.dat 67 102 Derived jet parameters
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See also:
J/AJ/130/1389 : Linear polarization of AGN jets at 15GHz (Lister+, 2005)
J/AJ/131/1262 : 15GHz circular polarization images of AGN jets (Homan+, 2007)
J/ApJS/171/376 : MOJAVE. III. VLA 1.4GHz images (Cooper+, 2007)
J/AJ/137/3718 : 15GHz monitoring of AGN jets with VLBA (Lister+, 2009)
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/ApJ/710/764 : Extended radio emission in MOJAVE blazars (Kharb+, 2010)
J/ApJ/722/L7 : Fermi/LAT detected MOJAVE AGNs (Pushkarev+, 2010)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Source IAU name (HHMM+DDd, B1950)
10- 19 A10 "YYYY-MM-DD" Epoch Epoch of observation
21- 26 F6.1 deg PAM [-180/180] 15.4GHz median jet position angle
28- 33 F6.1 deg PA1 [-180/180]?=- Position angle of the
15.4-8.1GHz core shift vector
35- 39 F5.3 mas Dr1 ?=- Magnitude of the 15.4-8.1GHz core shift
vector
41- 46 F6.3 mas Drp1 ?=- 15.4-8.1GHz core shift vector in
projection on the median position angle
48- 53 F6.1 deg PA2 [-180/180]?=- Position angle of the
15.4-8.4GHz core shift vector
55- 59 F5.3 mas Dr2 ?=- Magnitude of the 15.4-8.4GHz core shift
vector
61- 66 F6.3 mas Drp2 ?=- 15.4-8.4GHz core shift vector in
projection on the median position angle
68- 73 F6.1 deg PA3 [-180/180]?=- Position angle of the
15.4-12.1GHz core shift vector
75- 79 F5.3 mas Dr3 ?=- Magnitude of the 15.4-12.1GHz core shift
vector
81- 86 F6.3 mas Drp3 ?=- 15.4-12.1GHz core shift vector in
projection on the median position angle
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Byte-by-byte Description of file: table4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 8 A8 --- Source IAU source name (HHMM+DDd, B1950)
10- 19 A10 "YYYY-MM-DD" Epoch Epoch of observation
21 A1 --- Ocl [BQ] Optical classification: BL Lac or QSO
23- 27 F5.3 --- z Redshift
29- 33 F5.2 --- beta Apparent speed value (v/c)
35 A1 --- l_Dr1 Limit flag on Dr1
36- 40 F5.3 mas Dr1 15-8GHz core shift, Δrcore,15-8GHz
42 A1 --- l_Orv Limit flag on Orv
43- 47 F5.2 pc.GHz Orv Core shift measure, Ωrv
49 A1 --- l_B1 Limit flag on B1
50- 53 F4.2 10-4T B1 Magnetic field at 1pc (Gauss)
55 A1 --- l_Bcore Limit flag on Bcore
56- 59 F4.2 10-4T Bcore Core magnetic field (Gauss)
61 A1 --- l_rcore Limit flag on rcore
62- 67 F6.2 pc rcore Core radius at 15.6GHz
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History:
From electronic version of the journal
References:
Lister & Homan Paper I. 2005AJ....130.1389L 2005AJ....130.1389L Cat. J/AJ/130/1389
Homan & Lister 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
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
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) Patricia Vannier [CDS] 16-Nov-2012