J/MNRAS/442/3329 Rotation measures of 2642 quasars (Xu+, 2014)
Redshift evolution of extragalactic rotation measures.
Xu J., Han J.L.
<Mon. Not. R. Astron. Soc., 442, 3329-3337 (2014)>
=2014MNRAS.442.3329X 2014MNRAS.442.3329X
ADC_Keywords: QSOs ; Redshifts ; Galaxies, rotation
Keywords: ISM: magnetic fields - intergalactic medium - quasars: general -
radio continuum: ISM
Abstract:
We have obtained the rotation measures (RMs) of 2642 quasars by using
cross-identification of the most updated quasar catalogue and the RM
catalogue. After discounting the foreground Galactic Faraday rotation
of the Milky Way, we obtain the residual rotation measure (RRM) of
these quasars. We have carefully discarded the effects from
measurement and systematical uncertainties of RRMs as well as large
RRMs from RM outliers, and we have obtained marginal evidence for the
redshift evolution of the real dispersion of RRMs which steadily
increases to 10rad/m2 about z∼1 and is saturated at higher
redshifts. Ionized clouds in the form of galaxy halos, galaxy clusters
or cosmological filaments with different RM dispersion widths could
produce the observed RRM evolutions. However, current data sets cannot
constrain the contributions from galaxy halos and cosmic webs. Future
measurements of RMs for a large sample of quasars with high precision
are necessary to disentangle these different contributions.
Description:
We have obtained the RM data of quasars from the cross-identification
of quasars in the newest version of the Milliquas catalogue with radio
sources in the NVSS RM catalogue (Taylor et al., 2009ApJ...702.1230T 2009ApJ...702.1230T,
Cat. J/ApJ/702/1230) and the compiled catalogue (Xu & Han, 2014,
preprint (1405.1920)). The Milliquas catalogue (version 3.8a) is
a compilation of all known type I quasars, active galactic nuclei and
BL Lacertae objects in the literature (Flesch E., Million Quasars
Catalogue, Version 3.8. 2014. available online at
http://quasars.org/milliquas.htm)
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 87 2642 2642 quasars with RM data available in the literature
refs.dat 75 62 References
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 deg RAdeg Quasar Right ascension (J2000)
10- 17 F8.4 deg DEdeg Quasar Declination (J2000)
19- 23 F5.3 --- z [0.1/5.4] Quasar Redshift
25- 32 F8.4 deg GLON Galactic longitude
34- 41 F8.4 deg GLAT Galactic latitude
43- 49 F7.1 rad/m2 RM [-5359/4526] Observed rotation measure
51- 54 F4.1 rad/m2 e_RM [0.1/94] rms uncertainty on RM
56- 63 A8 --- r_RM Reference for RM, in refs.dat file
64- 69 F6.1 rad/m2 GRM [-143/150] Galactic rotation measure
71- 74 F4.1 rad/m2 e_GRM [0.5/57] rms uncertainty on GRM
76- 82 F7.1 rad/m2 RRM [-5377/4520] Extragalactic rotation measure
(RRM=RM-GRM)
84- 87 F4.1 rad/m2 e_RRM [0.7/95] rms uncertainty on RRM
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Ref Reference code
9- 27 A19 --- BibCode BibCode
29- 52 A24 --- Aut Author's name
54- 75 A22 --- Com Comments
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 27-Feb-2015