J/MNRAS/380/162 Aligned radio polarizations of quasars (Joshi+, 2007)
A survey of polarization in the JVAS/CLASS flat-spectrum radio source surveys.
II. A search for aligned radio polarizations.
Joshi S.A., Battye R.A., Browne I.W.A., Jackson N., Muxlow T.W.B.,
Wilkinson P.N.
<Mon. Not. R. Astron. Soc., 380, 162-174 (2007)>
=2007MNRAS.380..162J 2007MNRAS.380..162J
ADC_Keywords: Surveys ; QSOs ; Polarization
Keywords: polarization - surveys - galaxies: active
Abstract:
We have used the very large Jodrell Bank VLA Astrometric Survey/Cosmic
Lens All-Sky Survey 8.4-GHz surveys of flat-spectrum radio sources to
test the hypothesis that there is a systematic alignment of
polarization position angle vectors on cosmological scales of the type
claimed by Hutsemekers et al. (2005, Cat. J/A+A/441/915). The
polarization position angles of 4290 sources with polarized flux
density 1mJy have been examined. They do not reveal large-scale
alignments either as a whole or when split in half into high-redshift
(z≥1.24) and low-redshift subsamples. Nor do the radio sources which
lie in the specific areas covered by Hutsemekers et al.
(J/A+A/441/915) show any significant effect. We have also looked at
the position angles of parsec-scale jets derived from very long
baseline interferometry observations and again find no evidence for
systematic alignments. Finally, we have investigated the correlation
between the polarization position angle and those of the parsec-scale
jets. As expected, we find that there is a tendency for the
polarization angles to be perpendicular to the jet angles. However,
the difference in jet and polarization position angles does not show
any systematic trend in different parts of the sky.
Description:
We make use of the 4290 sources presented in Paper I (Jackson et al.,
Cat. J/MNRAS/376/371).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 16 1531 VLBI jet angles
tablea1.dat 91 52 The 52 common objects in JVAS/CLASS surveys and
Hutsemekers et al. sample (Cat. J/A+A/441/915)
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See also:
J/A+A/441/915 : Alignments of quasar polarization vectors (Hutsemekers+ 2005)
J/MNRAS/376/371 : Polarisation of flat-spectrum radio sources (Jackson+, 2007)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 11 A11 --- Name Name (JHHMM+DDMM or JHHMM+DDMMm)
13- 16 I4 deg JA Jet angle, measured from north through to east
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Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 h RAh Right ascension (J2000)
4- 5 I2 min RAm Right ascension (J2000)
7- 12 F6.3 s RAs Right ascension (J2000)
14 A1 --- DE- Declination sign (J2000)
15- 16 I2 deg DEd Declination (J2000)
18- 19 I2 arcmin DEm Declination (J2000)
21- 25 F5.2 arcsec DEs Declination (J2000)
27- 33 A7 --- OName Name for some sources
35- 39 I5 mJy F(8.4) Total flux at 8.4GHz
41- 46 F6.3 % P(8.4) Percentage polarized flux at 8.4GHz
48- 52 F5.2 % P(opt) Percentage polarized flux in optical
54- 58 F5.1 deg PA(8.4) Polarization position angle at 8.4GHz
60- 62 I3 deg PA(opt) Polarization position angle in optical
64- 68 F5.1 deg PAdiff Position angle difference, PA(opt)-PA(8.4)
70- 91 A22 --- Name Name (from Hutsemekers et al. (2005,
Cat. J/A+A/441/915)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 22-Jul-2008