J/ApJ/589/733 VLBI polarimetry of CJF sources (Pollack+, 2003)
VLBI polarimetry of 177 sources from the Caltech-Jodrell Bank
Flat-Spectrum Survey.
Pollack L.K., Taylor G.B., Zavala R.T.
<Astrophys. J. 589, 733 (2003)>
=2003ApJ...589..733P 2003ApJ...589..733P
ADC_Keywords: Radio sources ; Galaxies, radio ; QSOs ; Polarization
Keywords: galaxies: active - galaxies: jets - galaxies: nuclei - polarization -
quasars: general - radio continuum: galaxies
Abstract:
We present Very Long Baseline Array observations and a statistical
analysis of 5GHz VLBI polarimetry data from 177 sources in the
Caltech-Jodrell Bank Flat-Spectrum (CJF) survey. The CJF survey, a
complete, flux density-limited sample of 293 extragalactic radio
sources, gives us the unique opportunity to compare a broad range of
source properties for quasars, galaxies, and BL Lacertae objects. We
focus primarily on jet properties, specifically, the correlation
between the jet axis angle and the polarization angle in the core and
jet. A strong correlation is found for the electric vector
polarization angle in the cores of quasars to be perpendicular to the
jet axis. Contrary to previous claims, no correlation is found between
the jet polarization angle and the jet axis in either quasars or
BL Lac objects. With this large, homogeneous sample we are also able
to investigate cosmological issues and active galactic nucleus
evolution.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 92 177 Measured Source Properties
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See also:
J/ApJS/98/1 : First Caltech-Jodrell Bank VLBI Survey. I. (Polatidis+ 1995)
J/ApJS/98/33 : First Caltech-Jodrell Bank VLBI Survey. II. (Thakkar+ 1995)
J/ApJS/99/297 : First Caltech-Jodrell Bank VLBI Survey. III (Xu+ 1995)
J/ApJS/95/345 : Second Caltech-Jodrell Bank VLBI Survey. I. (Taylor+ 1994)
J/ApJS/100/1 : Second Caltech-Jodrell Bank VLBI Survey. II. (Henstock+ 1995)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 A8 --- Source B1950.0 source name (HHMM+DDd)
10- 11 I2 h RAh Right ascension (J2000.0)
13- 14 I2 min RAm Right ascension (J2000.0)
16- 21 F6.3 s RAs Right ascension (J2000.0)
23 A1 --- DE- Declination sign (J2000.0)
24- 25 I2 deg DEd Declination (J2000.0)
27- 28 I2 arcmin DEm Declination (J2000.0)
30- 35 F6.3 arcsec DEs Declination (J2000.0)
37 A1 --- Epoch [ABC] Epoch of observation (1)
39 A1 --- Parent [EP12] Parent sample (2)
41- 42 A2 --- Class [QGBLO ] Class (3)
44 A1 --- n_Class [njc] Sub-classification (4)
47- 49 I3 deg Theta ? Jet axis angle
51- 54 I4 mJy Icore Total intensity at the core
56- 57 A2 --- l_Pcore [≤ ] Limit flag on Pcore
58- 62 F5.1 mJy Pcore Total polarized intensity at the core (5)
64- 66 I3 deg Chicore ? Electric vector position angle at the core (6)
68- 71 F4.1 mas Length ? Jet length
73- 76 F4.1 mJy Pjet ? Average polarized intensity of detected jet
components
78- 79 I2 deg N ? Average difference between jet axis angle and
electric vector position angle in detected
jet components within 6mas of the core
81- 82 I2 deg F ? Average difference between jet axis angle and
electric vector position angle in detected
jet components farther than 6mas from the core
84- 87 F4.2 mJy e_Icore Total intensity rms noise
89- 92 F4.2 mJy e_Pcore Polarized intensity rms noise
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Note (1): Epoch as follows:
A = 1998
B = 1999
C = 2000
Note (2): Parent sample as follows:
P = PR; Pearson & Readhead, 1988ApJ...328..114P 1988ApJ...328..114P
1 = first Caltech-Jodrell Bank survey
(CJ1; Polatidis et al., 1995, Cat. J/ApJS/98/1)
2 = second Caltech-Jodrell Bank survey
(CJ2; Taylor et al., 1994, Cat. J/ApJS/95/345),
E = 8 sources not included in PR, CJ1, or CJ2 that complete the
Caltech-Jodrell Bank Flat-Spectrum survey
Note (3): Class as follows:
Q = quasar
G = galaxy
BL = BL lac object
O = Other
Note (4): Sub-classification as follows:
j = core-jet morphology
n = naked core morphology
c = compact symmetric object
Note (5): Cores with detected polarized intensities have
1σtypical∼0.2mJy
Note (6): Cores that meet detection criteria have 1σtypical∼4°
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History:
From electronic version of the journal
(End) James Marcout, Patricia Bauer [CDS] 26-Sep-2003