J/MNRAS/421/1861 OJ287 polarization and VLBI jet direction (Valtonen+, 2012)
Optical polarization angle and VLBI jet direction in the binary black hole
model of OJ287.
Valtonen M.J., Wiik K.
<Mon. Not. R. Astron. Soc., 421, 1861-1867 (2012)>
=2012MNRAS.421.1861V 2012MNRAS.421.1861V
ADC_Keywords: BL Lac objects ; Polarization
Keywords: galaxies: active - BL Lacertae objects: individual: OJ287 -
galaxies: jets
Abstract:
We study the variation of the optical polarization angle in the blazar
OJ287 and compare it with the precessing binary black hole model with
a "live" accretion disc. First, a model of the variation of the
jet direction is calculated, and the main parameters of the model are
fixed by the long-term optical brightness evolution. Then this model
is compared with the variation of the parsec-scale radio jet position
angle in the sky. Finally, the variation of the polarization angle is
calculated using the same model, but using a magnetic field
configuration which is at a constant angle relative to the optical
jet. It is found that the model fits the data reasonably well if the
field is almost parallel to the jet axis. This may imply a steady
magnetic field geometry, such as a large-scale helical field.
Objects:
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RA (2000) DE Designation(s)
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08 54 48.87 +20 06 30.6 OJ 287 = QSO J0854+2006
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 39 141 Historical data showing the mean direction of OJ287's
VLBI jet within the first 1mas from the core
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See also:
J/A+AS/129/569 : BVRI photometry of OJ 287 (Jia Guibin+ 1998)
J/AJ/132/1256 : eim BATC photometry of OJ 287 (Wu+, 2006)
J/AJ/141/65 : BATC ceimo light curves of OJ 287 (Dai+, 2011)
J/MNRAS/385/823 : UBVRI light curves of OJ 287 (Zheng+, 2008)
J/MNRAS/402/2087 : Optical polarization of OJ 287 in 2005-09 (Villforth+, 2010)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 7 F7.2 yr Obs Observation date
8 A1 --- n_Obs Day of Obs (1)
11- 16 A6 --- Array Array (2)
23- 25 F3.1 cm lambda Wavelength used at VLBI
28- 31 I4 deg PA [-140/130] Position angle of jet
33- 34 I2 deg e_PA ?=- rms uncertainty in PA (3)
36- 37 I2 --- Ref Reference (4)
39 A1 --- n_Ref [d] d: Data model-fitted by T.Savolainen.
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Note (1): Note on Obs.date as follows:
e = 1996 Oct 01
f = 1996 Oct 02
g = 1996 Oct 03
h = 1996 Oct 04
i = 1997 Jan 10
j = 1997 Jan 11
Note (2): Array as follows:
USVN = U.S. VLBI Network
Geo = Geodetic VLBI experiment
VLBA = Very Long Baseline Array
VLBA+ = VLBA and geodetic stations
VSOP = VLBI Space Observatory Programme
Note (3): If no error estimate is available, then e_PA=10deg is assumed.
Note (4): References as follows:
1 = Roberts et al. (1987ApJ...323..536R 1987ApJ...323..536R)
2 = Vicente et al. (1996A&A...312..727V 1996A&A...312..727V)
3 = Gabuzda et al. (1989ApJ...336L..59G 1989ApJ...336L..59G)
4 = Gabuzda & Cawthorne (1996MNRAS.283..759G 1996MNRAS.283..759G)
5 = Tateyama et al. (1999ApJ...520..627T 1999ApJ...520..627T)
6 = Fey et al. (1996ApJS..105..299F 1996ApJS..105..299F)
7 = VLBA 2cm Survey and MOJAVE program; Kellermann et al.
1998AJ....115.1295K 1998AJ....115.1295K, Lister et al. (2009, Cat. J/AJ/137/3718,
Cat. J/AJ/138/1874)
8 = Fey & Charlot (1997ApJS..111...95F 1997ApJS..111...95F)
9 = Jorstad et al. (2001ApJS..134..181J 2001ApJS..134..181J)
10 = Ojha et al. (2004ApJS..150..187O 2004ApJS..150..187O)
11 = Piner et al. (2007, Cat. J/AJ/133/2357)
12 = Gabuzda & Gomez (2001MNRAS.320...49K 2001MNRAS.320...49K)
13 = Tateyama & Kingham (2004ApJ...608..149T 2004ApJ...608..149T)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 04-Mar-2013